Year: 2022

Androgens are male hormones and as explained below, contribute to hair growth in both men and women. But, androgens also contribute to hair loss, such as in androgenetic alopecia. This is known as the “androgen paradox”.

As explained in the previous article, one of the main contributors to both male pattern baldness and female pattern baldness, also known as androgenetic alopecia, is the hormone dihydrotestosterone (DHT). DHT is a male hormone (androgen) that is a metabolite of testosterone made by the enzyme  5 alpha-reductase (5-AR) acting on testosterone. 

But androgens also play an important role in hair growth.

The Androgen Paradox

Before people go through puberty, most parts of the body (except for the scalp) are covered in thin, fine hair known as vellus hair (“peach fuzz”). Vellus hair is generally lighter and shorter than terminal hair that grows on the scalp, which is longer and thicker [1]. As androgens increase during puberty, vellus hair follicles are change into terminal hair follicles which then produce larger, curlier, and darker hair which appears in the public area, and “arm pits” (axillary area) [1].

During puberty, androgens stimulate beard growth in men [1], but even though androgens such as testosterone, androstenedione, dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS) are produced by the ovaries and adrenal glands of healthy women, these are not in large enough quantities to stimulate hair growth on the face. In women with Polycystic Ovarian Syndrome (PCOS) however, hair on the upper lip and chin area (hirsutism) is common and is believed to be due to high levels of male androgens and abnormal levels of luteinizing hormone (LH) from the pituitary interfering with the normal function of the ovaries [2,3].

Paradoxically, androgens also contribute to hair loss in androgenetic alopecia (AGA) [4].  A double blind control study from 1994 of people with androgenetic alopecia found that DHT levels were significantly higher in areas of bald scalp, than in areas of the scalp that contained hair [5]. In 1996, it was determined that the parts of the scalp that show balding in androgenetic alopecia have higher levels of the enzyme 5 alpha-reductase (5-AR) in the hair follicles, than the hair follicles in the parts of the scalp that do not bald [6]. These higher levels of 5-AR in the hair follicles converts testosterone to DHT, and when DHT binds to the receptors in the oil glands of hair follicles, it causes the follicles to shrink, or “miniaturize” until they eventually stop producing hair, resulting in baldness. 

As mentioned in the previous article, 5 alpha-reductase (5-AR) can be inhibited by the drug Finasteride® which lowers levels of DHT in the hair follicle, reducing the attack and slowing, or stopping hair loss.  Finasteride® also reduces the amount of DHT in the blood and scalp [7,8] and slowing androgenic alopecia progression.

As outlined in the first article in the three-part series titled, “Lotions, Potions, and Pills”, there are nutritional supplements available that are documented to restore hair growth and that are supported with the highest-quality evidence. A few of them are 5 alpha-reductase (5-AR) Inhibitors, and function similarly to Finasteride®.

The upcoming second article in the series will outline several oral hair growth supplement mixtures with the best quality scientific evidence to support hair growth — some of which also act as 5 alpha-reductase (5-AR) Inhibitors.

In addition, the third upcoming article in the series will outline evidence-based topical hair supplements that either serve as 5-AR reductase inhibitors to reduce the effect dihydrotestosterone (DHT) on hair follicles, support scalp health through their antibacterial or antimicrobial properties, or stimulate hair growth by increasing blood flow to hair follicles.

Final thoughts…

Androgens can paradoxically stimulate hair growth and cycling and this results in men having more hair on their face, and both men and women having hair in their pubic region and arm pits. Androgens can also contribute to balding on the scalp in the same individual, regardless of gender [9].

The balding effect of dihydrotestosterone (DHT) acting on hair follicles of the scalp can be reduced with use of medication treatment such as Finasteride®, as well as by evidence-based oral nutritional supplements and topical applications of essential oils, botanicals, and herbals.

While  Finasteride® is very effective at treating the hair loss associated with androgenic alopecia (as well as benign prostate hyperplasia (BPH)), its use is not without potential side effects. These can include decreased libido, the inability of men to have or maintain an erection, or problems with ejaculation [10]. 

Use oral nutritional supplements supported by robust scientific studies to promote hair growth and/or the use of topical applications of essential oils, botanicals, or herbals that have been demonstrated to be both safe and effective at reducing or stopping hair loss is also an available option.  Click here to read the first of three articles in a series on this topic.

More Info?

If you would like more information about how I could support you from a nutritional perspective, please send me a note through the Contact Me form at the top of this page.

To your good health!

Joy

You can follow me on:

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References

1. 1. Inui, S., Itami, S. (2013). Androgen actions on the human hair follicle: perspectives. Exp. Dermatol. 22, 168–171. doi: 10.1111/exd.12024
   2. Barbieri RL, Ehrmann, DA. UpToDate Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics), December 20, 2021, https://www.uptodate.com/contents/polycystic-ovary-syndrome-pcos-beyond-the-basics/
   3. Abdelazim IA, Alanwar A, AbuFaza M, et al. Elevated and diagnostic androgens of polycystic ovary syndrome. Prz Menopauzalny. 2020;19(1):1-5. doi:10.5114/pm.2020.95293
   4. Randall, V. A. (2007). Hormonal regulation of hair follicles exhibits a biological paradox. Semin. Cell Dev. Biol. 18, 274. doi: 10.1016/j.semcdb.2007.02.004
   5. Dallob, A. L., Sadick, N. S., Unger, W., Lipert, S., Geissler, L. A., Gregoire, S. L., et al. (1994). The effect of finasteride, a 5 alpha-reductase inhibitor, on scalp skin testosterone and dihydrotestosterone concentrations in patients with male pattern baldness. J. Clin. Endocr. Metab. 79, 703–706. doi: 10.1210/jcem.79.3.8077349
   6. Itami, S., Nakanishi, J., Yoshikawa, K., Takayasu, S. (1996). 21 Expression of androgen receptor, type I and type II 5 α-reductase in human hair follicle cells. J. Dermatol. Sci. 12, 86–86. doi: 10.1016/0923-1811(94)90434-0
   7. Drake, L., Hordinsky, M., Fiedler, V., Swinehart, J., Unger, W. P., Cotterill, P. C., et al. (1999). The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia. J. Am. Acad. Dermatol. 41, 550–554. doi: 10.1016/s0190-9622(99)80051-6
   8. Price, V. H. (1999). Treatment of hair loss. New Engl. J. Med. 341, 964–973. doi: 10.1056/NEJM199909233411307
   9. Miranda, B. H., Charlesworth, M. R., Tobin, D. J., Sharpe, D. T., Randall, V. A. (2018). Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life. FASEB J. 32, 795–806. doi: 10.1096/fj.201700260RR
   10. MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2022 Jun 15]. Finasteride, Available from: https://medlineplus.gov/druginfo/meds/a698016.html 

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People’s identity is tied to their appearance, which makes significant hair loss at any age or gender devastating, but can nutritional supplements help?

Those experiencing different types of hair loss are often desperate to find a solution, and there is no shortage of lotions, potions, and pills promising new hair growth. Are these safe and effective, or are they simply “snake oil”? This article is about evidence-based nutritional supplements that may help restore hair loss, depending on its cause. It’s important to keep in mind that nutrient needs between people differ, so supplementation is not one-size-fits-all.

Androgenic Alopecia

Androgenic alopecia is commonly known as “male pattern baldness” or “female pattern baldness,” and the leading cause of it is an androgenic hormone known as dihydrotestosterone (DHT). DHT binds to the hair follicle, causing it to shrink, and eventually, the hair stops growing entirely. Some nutritional supplements positively affect DHT and help support hair growth, but many “hair growth nutritional supplements” contain ingredients for which evidence of benefit is lacking.

A study at an alopecia clinic [1] found that 81% of the patients were female, and 63% of them used nutritional supplements, compared to the US average of 40% [2]. The most common hair loss supplements used include biotin, vitamin B12, and B-complex multivitamin and while taking these nutritional supplements may seem benign, biotin, for example, is well-known to interfere with diagnostic tests for Thyroid Stimulating Hormone (TSH). The implication of this is that people taking biotin-containing supplements to self-treat hair loss without first being evaluated for a thyroid disorder may result in missing the diagnosis and underlying cause of their hair loss. In addition to interfering with diagnostic tests, some ‘hair loss nutritional supplements’ may be toxic in high doses, while still others may interact with medications, or supplements that people are taking to restore a diagnosed nutrient deficiency [3]. 

A systematic review that was recently published in the Journal of the American Medical Association (JAMA) Dermatology (November 30, 2022) evaluated the effectiveness of nutritional supplements for treating hair loss in people without nutritional deficiency [4]. This first article is based on this current systematic review.

Three Main Types of Hair Loss

There are three main types of hair loss, telogen effluvium, androgenic alopecia (AGA), and alopecia areata (AA).

Telogen effluvium (TE) is the most common form of diffuse hair loss [5] and usually occurs after a profound stress, shock or traumatic event including childbirth,  a thyroid disorder, or rapid weight loss. This type of hair loss was covered in this earlier article. But TE is not the only type of hair loss in hypothyroidism. In a study of more than 1200 people with thyroid disorder, half (50%) of people aged 40 years old and older had either alopecia areata, or androgenetic alopecia [6].

Androgenic alopecia (AGA) affects up to 50% of men and women. In men is called ‘male pattern baldness’ and is mainly seen on the crown of the head and the temples. In women, it is called ‘female pattern baldness’ and is primarily seen at the crown of the head, with a broader center part. Androgenic alopecia is a genetic disorder that involves both maternal (mother’s) and paternal (father’s) genes, with sons being 5-6 times more likely to have it if their fathers were balding [7]. 

Alopecia areata (AA) is an autoimmune disorder where the body’s immune system attacks the follicles. As a result, hair often comes out in clumps, usually the size and shape of a quarter, but it can affect more expansive areas of the scalp [8]. It can occur in those with other autoimmune conditions, including thyroid disease. 

There are medication treatments available for the different types of hair loss, and there is increasing evidence that taking specific nutritional supplements can be helpful in helping restore hair loss.

A systematic review published in JAMA Dermatology [4] published November 30, 2022 — just a month ago, evaluated the effectiveness of nutritional supplements for treating hair loss in people without nutritional deficiency. The dietary supplements with the highest-quality evidence of potential benefit were categorized according to their mechanism of action and are outlined in this article.

Dihydrotestosterone (DHT) as a Main Cause of Hair Loss

One of the main contributors to androgenetic alopecia (AA) is the male hormone (androgen) called dihydrotestosterone (DHT). DHT is made by an enzyme called 5 alpha-reductase (5-AR) acting on testosterone. When DHT binds to the receptors in the oil glands of hair follicles, it causes the follicles to shrink, shortening their life span. Eventually, these follicles shrink so much that they stop producing hair. The end result is baldness. DHT can be suppressed by medications such as Finasteride®, which lowers levels of DHT. This reduces the attack on hair follicles, slowing or stopping hair loss.

(Minoxidil® is a hair loss medication that works by an entirely different mechanism. It acts as a vasodilator, increasing blood flow in the scalp by making blood vessels wider. It is thought that this increased blood flow slows hair loss and encourages hair to regrow.)

[Update, December 29, 2022: While androgens such as DHT contribute to baldness by their detrimental effect on hair follicles in the scalp, androgens like DHT are also a key player in hair growth. This contradictory role of androgens is known as the “androgen paradox”. This short supplemental article explains more. ]

Nutritional Supplements – the role of 5-α reductase (5-AR) inhibitors in restoring hair loss

Pumpkin Seed Oil as a nutritional supplement in hair loss

Pumpkin seed oil is known to be effective in treating benign prostate hyperplasia (BPH) because it acts as a 5AR inhibitor [9,10], so it was an excellent candidate to study for its effect on hair growth. In a 2014 study, 76 male androgenic alopecia (AGA) patients were divided into two groups. For 24 weeks, one group of subjects took a 400 mg capsule of pumpkin seed oil each day, while the other group took a placebo. The group taking the pumpkin seed oil nutritional supplement showed significantly superior hair growth, with a mean hair count increase of 40% in the pumpkin seed oil-treated men compared to 10% in the placebo-treated men. There were no differences in adverse effects between the two groups.

Nutritional Supplements in Hair Loss – Saw Palmetto

In a 2004 pilot study, six of ten subjects (60%) that took an extract made from 200 mg Saw Palmetto extract (Serenoa repens), 50 mg betasitosterol, along with 50 mg lecithin, 100 mg inositol, 25 mg phosphatidyl choline, 15 mg niacin, and 100 μg biotin for 5 months were reported to have improved hair growth compared to the placebo controlled group (11%), however the difference was not statistically significant [11]. Studies with larger groups of both treatment and control groups is needed before conclusions can be made. Most importantly, it is hard to know if the benefits were due to the Saw Palmetto, or some of the other ingredients in the supplement.  For this reason, I think this next study is more helpful.

A two year randomized control study of 100 male patients with mild to moderate androgenic alopecia took either 320 mg of dry Saw Palmetto nutritional supplement extract (Serenoa repens) daily for 24 months, or 1 mg Finasteride daily for the same time period.  While Finasteride was significantly more effective at slowing hair loss, at 24-months the Saw Palmetto extract did stabilize hair loss. [12].

The results of this study suggest that Saw Palmetto can stabilize hair loss over two years, but is less effective than the medication Finasteride.

The Role of Specific Micronutrients in Restoring Hair Loss

Nutritional Supplements for Hair Loss – Vitamin D

Three studies from the last 5-10 years have demonstrated that that lower levels of vitamin D, or vitamin D deficiency have been associated with all three forms of hair loss, including androgenic alopecia [13], alopecia areata [14], and telogen effluvium [15].

A small 2021 study supplemented 40 women with telogen effluvium with very high oral vitamin D3 (200,000 IU every two weeks for six weeks). The study reported that more than 80% had improved results on a hair pull test after six months, with no adverse side effects [16]. However, the limitation of this study was that it was unknown if any of these subjects were deficient in vitamin D before taking the supplements, there was no control group, and telogen effluvium tends to resolve by itself over the same six-month period without treatment.

Before beginning supplementation, it would be prudent to assess vitamin D status and to determine how low or deficient it is, then increase dietary intake of vitamin D, and supplement as necessary to attain and maintain sufficient blood levels of vitamin D.

Foods that are naturally good sources of vitamin D include fatty fish such as salmon, mackerel and tuna.

Nutritional Supplements for Hair Loss – Zinc

A deficiency of zinc is associated with telogen effluvium, and lower zinc levels have been observed in people with alopecia areata (AA) [17-19]. Two small studies of zinc supplementation in patients with alopecia areata both reported benefits. The first study with 38 subjects was from 1981 [20] and supplemented using 220 mg of zinc sulfate per day. The second study from 2012 [21] had 67 subjects supplemented with 5 mg/kg body weight per day of zinc sulfate. Both studies reported benefits at three months; however, larger studies are needed.

It would be best to assess zinc status for those with hair loss (especially alopecia areata) prior to supplementing with zinc.

If zinc status is low, increasing dietary intake of zinc would be a great place to start. Good sources of zinc include red meat, poultry, seafood such as oysters, crab, lobster, and sea urchin (uni, in Japanese), as well as nuts.

If needed to achieve adequate blood levels of zinc, a supplement can be added to attain, and maintain zinc adequacy, but it’s important to ensure there is adequate copper intake as well, as zinc depletes copper. Beef liver is a very good source of dietary copper, but eating 3 or 4 ounces once a week may be enough, as it has 6 times the recommended dietary intake of copper, and high amounts of preformed vitamin A. It is also important not to take zinc supplements within several hours of taking iron supplements, as they complete for binding sites.

Nutritional Supplements for Hair Loss – Vitamin B12

Vitamin B12 is necessary for DNA synthesis and it was proposed in a 2017 report on the role of micronutrients in alopecia areata that vitamin B12 could be helpful in increasing the number of hair follicles [17].

A 2018 study of people with telogen effluvium that included symptoms of itching, pain, soreness, and/or burning were evaluated for symptoms of B12 deficiency. While lab normal values were 200-400 pg/mL, deficiency was evaluated to be <550 pg/ml, a cutoff limit reported to be used in other countries. After four months, 90% of subjects that received either a daily B12 tablet or monthly B12 injection had significant decrease or even an absence of hair shedding [23]. The main shortcoming of this study was the self-resolving nature of telogen effluvium — which means that over the same period of time, doing nothing could have resulted in improvement is hair loss.

The best dietary sources of vitamin B12 are organ meats, including liver and kidney, clams, sardines, and beef, however, some disorders and advanced age can result in reduced dietary absorption of vitamin B12. Testing vitamin B12 status is important especially in older adults who have decreased absorption of B12 due to decreased intrinsic factor, as well as testing B12 status in those taking medication to lower stomach acid. 

Nutritional Supplements – the role of antioxidants in restoring hair loss

Oxidative stress has been thought to play a role in all three types of hair loss [24-26] and antioxidants such as selenium, vitamins A, E and C, and carotenoids (yellow, orange or red coloured fat-soluble pigments found in vegetables, fruit, and some fish. 

A 2015 randomized control study compared the effects of giving a supplement containing omega 3 fat from fish, omega 6 fat from blackcurrant seed oil, as well as the antioxidants lycopene (from tomato), vitamin C, and vitamin E versus giving no supplement to 188 women diagnosed with stage 1 androgenic alopecia [27]. The intervention group had significantly increased hair density and hair thickness at six months.

A 2010 randomized control study compared giving a supplement containing mixed tocotrienol from the vitamin E family versus a placebo to patients with unspecified hair loss. The 50 mg mixed capsules given to the intervention group had 30.8% alpha-tocotrienol, 56.4% gamma-tocotrienol, and 12.8% delta-tocotrienol, as well as 23 IUs alpha-tocopherol). Twenty one subjects were randomly assigned receive 2 x 50 mg (100 mg) of mixed tocotrienols daily, while 17 subjects were assigned to receive an oral placebo capsule. At 8-months, the number of hairs of the subjects in the intervention group increased by 34.5% compared to the placebo group which had a 0.1% decrease [28]. The shortcomings of this study were the small sample size and that the study did not define hair loss in the inclusion criteria of subjects. 

Nutritional Supplements – more is not always better

Caution needs to be taken when choosing types and amounts of antioxidant supplements as excessive use of supplements such as selenium, for example has been tied both to toxic effects and hair loss [29]. Even when getting selenium in the diet by eating Brazil nuts, only 2 is already at the maximum daily amount. Eating 4 or 5 Brazil nuts can exceed the safe upper tolerance of selenium for adults, so more is not better. 

Excess vitamin A intake can result in vitamin A intoxication which can result in seizures or blurred vision, and long term (chronic) over supplementation with vitamin A can result in several symptoms, including muscle and bone pain, high blood lipids and ironically alopecia, or hair loss [30].

The best sources of preformed vitamin A (retinol) are beef liver, fish, and eggs and a delicious and very rich source is Icelandic cod livers.

Cod livers are very high in retinol, and just half a 115g can contains 450% the recommended daily intake for vitamin A. To avoid getting too much preformed vitamin A, it is best not to eat cod livers more than once every week or two, and even further apart if also regularly consuming beef liver which is also high in preformed vitamin A.

Before beginning to take supplements it is important to assess intake form food sources, so as not to take too much as a supplement.

Other Nutritional Supplements – probiotics and growth hormone modulators

Probiotics have been hypothesized to improve blood flow to the scalp and one study from 2020 used a kimchi and fermented soybean paste (cheonggukjang) probiotic product.

Twenty-three men and twenty-three women with androgenic alopecia (AGA) were given the supplement and at four months, 93% showed significant improvement in either hair thickness and/or hair count, with no serious side effects [31]. The limitations of this study were the small sample size and lack of a control group.

Capsaicin, is the chemical that give hot chilis their spiciness and is used as a topical pain reliever. When  applied to the scalp has been found to increase Insulin-like Growth Factor I (IGF-1) which is involved in hair growth [32].

A randomized control study of a capsaicin and isoflavone supplement (6 mg capsaicin, 75 mg isoflavone (from soy) in 48 adults with either androgenic alopecia (AGA) or alopecia areata (AA) compared to controls found significantly more hair growth in the capsaicin and isoflavone group at 5 months, and no adverse effects were reported. The limitations of this study were its small sample size as well as the inclusion of various types of alopecia.

Final Thoughts…

In the United States, dietary supplements are normally considered a food and as such, their safety or effectiveness are not evaluated by the Food and Drug Administration (FDA). It is only if a product is labelled to treat a disease that the product meets the definition of a drug and needs to establish its efficacy [33].

In Canada, however, dietary supplements are considered Natural Health Products (NHP) by Health Canada and are treated as non-prescription drugs which are regulated under the Natural Health Product Regulations. According to Health Canada, in the ten years from 2004 (when the Natural Health Product Regulations came into existence) and 2014, nearly 55,000 licenses for NHPs were issued [34].

The ease by which Canadians can order supplements online from the US essentially bypasses any governmental safeguards put into place by Health Canada so it is important that people in both countries are aware that there is no FDA oversight for safety or efficacy for supplements purchased from the US. For this reason, it is best that before people begin using dietary supplements to self-treat hair loss, that they discuss this with a knowledgeable healthcare professional, such as their doctor or Registered Dietitian. In addition, for those already taking dietary supplements, it is important before going for lab tests to mention to your doctor and Dietitian which supplements you are taking so that they can ensure that you discontinue use of specific supplements for an sufficiently long period of time before the test (such biotin before a Thyroid Stimulating Hormone (TSH) test).

More Info?

Hair loss can be devastating, but before parting with substantial sums for money for lotions, potions, or pills that promise new hair growth, first take the time to find out what you need. 

Consider finding out if your diet or lifestyle may put you at risk for nutrient deficiencies, and if so to have those evaluated. Ask yourself if it is possible you may have a thyroid disorder (this article may help) so that you can have diagnostic tests before taking supplements that can interfere with getting accurate results.

Finally, if blood tests come back indicating that you may have low nutrient status or a deficiency, find out which nutrients can be adequately obtained from food, and which may need to be supplemented.

Nutritional supplements can be very helpful if used correctly, but taken in the wrong dosage, or at the wrong timing, supplements can interfere with the absorption of medications you may take, and/or with other nutrients you are already low on.

If you would like more information on how I can help assess your dietary intake or nutrient status of specific nutrients, please send me a note through the Contact Me form at the top of this page.

To your good health!

Joy

You can follow me on:

Twitter: https://twitter.com/JoyKiddie
Facebook: https://www.facebook.com/BetterByDesignNutrition/

References

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   2. E.D. Kantor, C.D. Rehm, M. Du, E. White, E.L. Giovannucci, Trends in dietary supplement use among U.S. adults from 1999–2012, JAMA, 316 (14) (2016), pp. 1464-1474
   3. Ronis MJJ, Pedersen KB, Watt J. Adverse effects of nutraceuticals and dietary supplements. Annu Rev Pharmacol Toxicol. 2018;58:583-601. doi:10.1146/annurev-pharmtox-010617-052844
   4. Drake L, Reyes-Hadsall S, Martinez J, Heinrich C, Huang K, Mostaghimi A. Evaluation of the Safety and Effectiveness of Nutritional Supplements for Treating Hair Loss: A Systematic Review. JAMA Dermatol. Published online November 30, 2022. doi:10.1001/jamadermatol.2022.4867
   5. Malkud S. Telogen Effluvium: A Review. J Clin Diagn Res. 2015;9(9):WE01-WE3. doi:10.7860/JCDR/2015/15219.6492
   6. Vincent M, Yogiraj K. A descriptive study of alopecia patterns and their relation to thyroid dysfunction. Int J Trichol 2013;5:57-60
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   24. Prie BE, Iosif L, Tivig I, Stoian I, Giurcaneanu C. Oxidative stress in androgenetic alopecia. J Med Life. 2016;9(1):79-83.
   25. Savci U, Senel E, Oztekin A, Sungur M, Erel O, Neselioglu S. Ischemia-modified albumin as a possible marker of oxidative stress in patients with
       telogen effluvium. An Bras Dermatol. 2020;95(4): 447-451. doi:10.1016/j.abd.2020.01.005
   26. Öztürk P, Arıcan Ö, Kurutaş EB, Mülayim K. Oxidative stress biomarkers and Adenosine deaminase over the alopecic area of the patients with alopecia areata. Balkan Med J. 2016;33(2):188-192. doi:10.5152/balkanmedj.2016.16190
   27. Le Floc’h C, Cheniti A, Connétable S, Piccardi N, Vincenzi C, Tosti A. Effect of a nutritional supplement on hair loss in women. J Cosmet
       Dermatol. 2015;14(1):76-82. doi:10.1111/jocd.12127
   28. Beoy LA,WoeiWJ, Hay YK. Effects of tocotrienol supplementation on hair growth in human volunteers. Trop Life Sci Res. 2010;21(2):
       91-99.
   29. Sutter ME, Thomas JD, Brown J, Morgan B. Selenium toxicity: a case of selenosis caused by a nutritional supplement. Ann Intern Med. 2008;148
       (12):970-971. doi:10.7326/0003-4819-148-12-200806170-00015
   30. Olson JM, Ameer MA, Goyal A. Vitamin A Toxicity. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.
   31. Park DW, Lee HS, Shim MS, Yum KJ, Seo JT. Do kimchi and cheonggukjang probiotics as a functional food improve androgenetic alopecia? a clinical pilot study. World J Mens Health. 2020;38 (1):95-102. doi:10.5534/wjmh.180119
   32. Harada N, Okajima K. Effect of topical application of capsaicin and its related compounds on dermal insulin-like growth factor-I levels in mice
       and on facial skin elasticity in humans. Growth Horm IGF Res. 2007;17(2):171-176. doi:10.1016/j.ghir. 2006.12.005
   33. US Food and Drug Administration. Questions
       and Answers on Dietary Supplements. Accessed December 27, 2022. https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements
   34. Health Canada, Natural Health Products Program Quarterly Snapshot – Quarter 1 (Fiscal year 2014-2015), https://www.canada.ca/en/health-canada/services/drugs-health-products/natural-non-prescription/activities/quarterly-snapshot-quarter-1-2014-2015.html

Copyright ©2022 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

Hypothyroid 101 provides an overview of what the thyroid does, the main thyroid hormones, the main causes of hypothyroidism, how hypothyroidism is diagnosed, as well as options for having thyroid blood tests done.

The Thyroid Gland

The thyroid is butterfly-shaped gland situated in the middle of the lower front part of the neck. While it isn’t very big, it plays a very important role in the regulation of metabolism which is the process by which the food we eat is converted to energy.

When the thyroid doesn’t function properly, it affects metabolism. In the case that the thyroid is underactive (hypothyroid) this results in a slowing of everything from heart rate, our ability to generate heat to stay warm, for muscles to do work, and for us to think properly and process information.

The Two Main Thyroid Hormones – T4 and T3

The thyroid produces two main hormones, T4 (thyroxine) and T3 (triiodothyronine). When it’s working properly, 93% of the thyroid hormone produced by the body each day is T4, and only 7% is T3 [1]. The thyroid manufactures ~85mcg of T4 and 6.5mcg of T3 per day [1], which is a T4 to T3 ratio of 13:1.  

T4 is the inactive form of thyroid hormone and has four molecules of iodide bound to it. When it becomes activated, it loses one of the iodides and becomes T3, which is the active form.

In its free, unbound form, thyroxine is known as free T4 (abbreviated fT4) and in its free, unbound form triiodothyronine is known as free T3 (abbreviated fT3). 

The production of T4 and T3 in the thyroid is regulated by the pituitary gland, but the signal for the pituitary gland to tell the thyroid gland to make thyroid hormones comes from the hypothalamus region of the brain.  The hypothalamus releases a hormone called TRH (Thyrotropin-Releasing Factor) that acts on the pituitary gland, causing it to release a hormone called TSH (Thyroid Stimulating Hormone). It is TSH released from the pituitary gland that acts on the thyroid gland, causing it to release thyroxine.

Hypothyroid – how it is diagnosed

In Canada and many places in the US, the standard screening test for abnormal thyroid function, including hypothyroid, is a blood test measuring thyroid stimulating hormone (TSH), which is a pituitary hormone. 

If TSH results falls within normal range, no testing of thyroid hormones occurs. The thyroid response to TSH is presumed to be normal. 

Central Hypothyroidism occurs when there is a problem with either the hypothalamus or the pituitary gland.

On lab tests, a low TSH and low free T4 indicates central hypothyroidism and this is often treated by prescribing medication, including T3 containing medications. 

Primary hypothyroidism is where there is no abnormality in the hypothalamus or the pituitary gland. It is diagnosed when there is high TSH, and normal or low free T4.

Hypothyroid – main causes 

In the developed world, the most common form of primary hypothyroid in is Hashimoto’s disease. In developing countries, it is mostly caused from a lack of iodine in the diet. Other causes of hypothyroid includes the trauma from surgery to remove a benign or cancerous tumour, or the result of radioactive iodine treatment for overactive thyroid.

Hashimoto’s disease is the most common cause of hypothyroid in the West. It is an autoimmune disorder where the body’s immune system, specifically the lymphocytes attack the thyroid. In response to this attack,  the thyroid produces antibodies, specifically thyroperoxidase antibodies (TPO-ab) and thyroglobulin antibodies (TG-ab) [3]. A diagnosis of Hashimoto’s is made based on both the presence of symptoms of hypothyroidism, as well as the presence of TPO-ab or TG-ab.

One of the main challenges with getting diagnosed as hypothyroid is that many of the early symptoms of hypothyroidism are non-specific  — meaning they can have several different causes.

In a post-pandemic world of telephone doctor appointments, such vague symptoms may seem too inconsequential to bring up.

Below is a downloadable checklist that can help you have a conversation with your doctor.

Symptoms such as body aches, joint pain, fatigue, feel chilled, weight gain, frequently being constipation, having dry skin don’t seem ‘serious’ enough to make an appointment with one’s doctor and could be due to a number of different causes from  not eating well, to having a virus, and are very often discounted as being due to “age”. Even forgetfulness and depression which are known symptoms in more advanced hypothyroidism are often attributed to aging. 

Hypothyroid – getting evaluated and diagnosed 

As outlined in an earlier article, in British Columbia unless a person is of advanced age, has a family history or personal medical history of thyroid disease or another autoimmune disorder, takes medications such as lithium or amiodarone, or is from a developing country with iodine deficiency, they do not even qualify for TSH testing unless they display the specific symptoms listed in Table 1, below [4].

One drawback to the above approved checklist is that it does not include some of the well-documented symptoms of hypothyroidism, such as non-pitting edema of the lower legs and ankles, a puffy swollen face, an enlarged tongue (with or without scalloped edges), loss of the outer third of eyebrows, or having pale or bluish lips.

Even if one has a blood test for TSH, if it comes back at the high end of the normal range, no further testing is done [4]. 

Without a person having known risk factors, or having symptoms that appear in the official  list in the Guidelines and Protocols [4] (Table 1, above), diagnostic tests may not be requisitioned unless or until a person becomes sicker and the reason for this is explained below, in the section about ordering lab tests.

To help people have an informed discussion with their doctor, below is a 2-page downloadable, fillable checklist that contains a list of common hypothyroid symptoms, along with a simple explanation of what that symptom is. For example, in this checklist “periorbital edema” is explained as ‘swelling under eyes.’

Please note that this checklist list is not exhaustive and is NOT intended to be used for self-diagnosis purposes. It is only provided so that people who think they may have symptoms of hypothyroidism can consult with their doctor, and discuss the matter with them. Remember, only a medical doctor can diagnose and treat. 

Signs and Symptoms of Hypothyroidism – 2-page downloadable and fillable checklist

• • • TSH: $9.90
    • free T4: $12.12
    • free T3: $9.35
    • thyroperoxidase antibody (TPO-ab): $20.22 (payable only for possible autoimmune thyroid disease)
    • thyroglobin antibody (TG-ab): $27.90 (only performed as an adjunct to thyroglobulin measurement for the conditions such as thyroid tumors, cancer, etc.)
    • reverse T3: uninsured test 

• • TSH
  • Free Thyroxine (FT4)
  • Free Triiodothyronine (FT3)
  • Reverse T3
  • Thyroperoxidase Antibody (TPO-ab)
  • Anti-Thyroglobulin (TG-ab)

3. Patient-Pay 

1. Jonklaas J, Bianco AC, Bauer AJ, et al, Guidelines for the treatment of hypothyroidism: prepared by the American thyroid association task force on thyroid hormone replacement. thyroid. 2014 Dec 1;24(12):1670-751.
2. Berkow, R., Beers, M. H., & Fletcher, A. J. (1997). The Merck Manual of Medical Information. Whitehouse Station, N.J.: Merck Research Laboratories.
3. Puszkarz, Irena, Guty, Edyta, Stefaniak, Iwona, & Bonarek, Aleksandra. (2018). Role of food and nutrition in pathogenesis and prevention of Hashimoto’s thyroiditis. https://doi.org/10.5281/zenodo.1320419
4. BC Guidelines & Protocols Advisory Committee, Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder, October 24, 2018
5. Laboratory Services Act, Laboratory Service Regulation, October 1, 2015 (last amended September 20, 2020 by B.C. Reg. 263/2020)

Copyright ©2022 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

DISCLAIMER (October 14, 2022): The information in this post and in the checklist contained in it should in no way be taken as a recommendation to self-diagnose, self-interpret diagnostic tests, or self-treat any suspected disorder. It is essential that people who suspect they may have symptoms of any condition consult with their doctor, as only a medical doctor can diagnose and treat.

As outlined in a previous article, the standard screening test for abnormal thyroid function is thyroid stimulating hormone (TSH), but if those results come back within normal range and a person has not known risk factors or obvious symptoms of thyroid disease, no testing of thyroid hormones occurs,  and thyroid function is presumed to be normal.

In British Columbia, unless a person is of advanced age, has a family history or personal medical history of thyroid disease or an autoimmune disorder, takes medications such as lithium or amiodarone, or is from a a developing country with iodine deficiency, they do not qualify for TSH testing unless they display the specific symptoms listed in Table 1, below.

This approved checklist does not include some of the well-documented symptoms of hypothyroidism, such as non-pitting edema of the lower legs and ankles, a puffy swollen face, enlarged tongue with or without scalloped edges, loss of the outer third of eyebrows, or having pale or bluish lips. The downloadable checklist below contains a list of these, and other common symptoms.

Signs and Symptoms of Hypothyroidism – downloadable checklist

This downloadable checklist of common hypothyroid symptoms is not intended to self-diagnose. It is provided to help people who feel unwell to have an informed discussion with their doctor as to whether thyroid hormone testing should be considered.

Signs and Symptoms of Hypothyroidism – larger type, 4-page downloadable checklist

   NEW – Signs and Symptoms of Hypothyroidism – 2-page downloadable and fillable checklist

More Info?

If you would like to know how I can help support your nutritional needs, please send me a note through the Contact Me form.

To your good health!

Joy

You can follow me on:

Twitter: https://twitter.com/JoyKiddie
Facebook: https://www.facebook.com/BetterByDesignNutrition/

References

1. BC Guidelines & Protocols Advisory Committee, Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder, October 24, 2018

Copyright ©2022 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

Diagnosis and Treatment

The most recent population-based study data from the US with almost 26,000 adults aged 18 – 74 years found 9.5% had TSH levels >5.1 mIU/L, with a higher prevalence in women and older adults. Among the 9.5% with elevated TSH, 74% had subclinical hypothyroidism (TSH 5.1 and 10 mIU/L), and 26% had overt hypothyroidism (TSG >10 mIU/L) [17].

Note (August 14, 2022): From a practical point of view, this study shows that almost 10% of adults have some form of hypothyroidism, with 7/10% being subclinical and 2½ % having clear hypothyroidism. Given its prevalence and significant risk of being undiagnosed, identifying symptoms and lab markers before it progresses is essential. 

In British Columbia, a diagnosis of subclinical hypothyroidism is made at a TSH > 4 mIU/L, but treatment is only recommended when TSH is above 10 mIU/L [18]. This leaves those with a TSH >4 mIU/L but <10 mIU/L in the situation where they need to get much sicker before treatment is recommended.

The goal of treatment with thyroid hormone replacement is to reduce the patient’s serum TSH concentration into the normal reference range. Since the mean serum TSH for the general population is around 1.4 mIU/L, with 90% having serum TSH levels <3.0 mIU/L, many experts recommend a therapeutic TSH target ranging from 0.5 to 2.5 mIU/L in young and middle-aged patients [19] to 7.7 mIU/L in elderly people over the age of 80 years [20].

Studies with 10 to 20-year follow-up have reported that 33 to 55% of people with subclinical hypothyroidism progress to overt hypothyroidism [21,22,23]. This means that 1/3 to >1/2 of people with subclinical hypothyroidism will develop overt hypothyroidism within that period.

Most experts do not recommend treating people with a TSH > 10 mIU/L but with no symptoms (asymptomatic). However, since a meta-analysis of data from 1950-2010 found no increased risk of coronary heart disease in asymptomatic people with a TSH of 4.5 to 6.9 mIU/L, treating them is generally not recommended [24]. 

There is, however, an increased risk of coronary heart disease in those with a TSH of 7.0 to 9.9 mIU/L, so some experts recommend treating those with a TSH > 7.0 mIU/L whether or not they have symptoms [24]. Unfortunately, despite this elevated risk, individuals in British Columbia do not currently have access to treatment with a TSH < 10 mIU/L under the guidelines [18].

Final Thoughts…

Making recommendations on how someone should change their diet can’t be made in a vacuum and it is for this reason, I evaluate a person’s lab test results in light of their medical history and enquire about family history of type 2 diabetes, heart disease, high cholesterol, blood pressure, thyroid disorders and other conditions as part of my assessment. Then I look at how people eat in light of their risk factors for those conditions.

If I feel that it would be beneficial to have additional lab work such as fasting insulin, or thyroid stimulating hormone (TSH), then I will request that their doctor requisition these tests. Often, when I provide the doctor with my clinical reasons for asking for them, they write the requisition; however, sometimes, they decline. If I don’t think it would not be a financial burden and that having the results will provide the client with a much better understanding of how their diet relates to their weight or health, I will discuss the option of obtaining the tests on a patient-pay basis.  If self-paying for the tests is not feasible, and the risk factors are significant, then I will tailor my dietary recommendation to lower the risk.

NOTE (August 15, 2022): It is important to keep in mind that too little, or too much thyroid hormone can have serious consequences.

Untreated or under-treated hypothyroidism can be serious and is when the body gets too little thyroid hormone. This can lead to a myxedema crisis (covered in this article).

Thyrotoxicosis can also be serious and is when the body gets too much thyroid hormone. This can occur in untreated hyperthyroidism, or by self-treating hypothyroidism (covered in this article).

More Info

If you would like more information about how I can support you in your goal of improved health, please send me a note through the Contact Me form above.

To your good health!

Joy

You can follow me on:

Twitter: https://twitter.com/JoyKiddie
Facebook: https://www.facebook.com/BetterByDesignNutrition/

DISCLAIMER (August 14, 2022): The information in this post should in no way be taken as a recommendation to self-diagnose, self-interpret diagnostic tests, or self-treat any suspected disorder, including thyroid function. It is essential that people who suspect they may have symptoms of any condition consult with their doctor, as only a medical doctor can diagnose and treat.

In Canada and many places in the US, the standard screening test for abnormal thyroid function is thyroid stimulating hormone (TSH). As outlined below, TSH is a hormone that is released from the pituitary gland, not the thyroid. If TSH results falls within normal range, no testing of thyroid hormones occurs. Thyroid response to TSH is presumed to be normal.

Thyroid Hormones and Lab Tests Used to Assess Thyroid Function

Thyroid Stimulating Hormone (TSH) is a hormone that is produced by the pituitary gland in response to a hormone called Thyrotropin-Releasing Factor (TRF) that is released by the hypothalamus of the brain.

Thyroid Stimulating Hormone (TSH) released from the pituitary gland acts on the thyroid gland, a butterfly shaped gland in the front of the neck. The action of pituitary TSH on the thyroid results in the release of thyroxine, also called Free T4 (fT4).  Thyroxine (fT4) is reduced to Triiodothyronine also called Free T3 (fT3), which is the active form of thyroid hormone.

Central Hypothyroidism is where a problem exists in either the hypothalamus or the pituitary gland that results in a decreased in TSH release from the pituitary gland. On lab tests, a low TSH and low T4 indicates central hypothyroidism. This is often treated by administration of growth hormone, or using T3 containing medications. 

Primary hypothyroidism is where there is no abnormality in the hypothalamus or the pituitary gland. Primary hypothyroidism is diagnosed when there is high TSH and normal or low free thyroxine (free T4 / fT4). In many places in Canada and the USA, if TSH is normal, no further testing is done. It is assumed that the action of pituitary TSH on the thyroid gland results in sufficient release of T4.

Thyroid Function – different causes of primary hypothyroidism

Hashimoto’s Disease

The most common form of primary hypothyroidism in the western world is Hashimoto’s disease which is an autoimmune disorder where the body attacks the thyroid. Thyroid Peroxidase Antibody (TPO antibody) is the marker for Hashimoto’s hypothyroidism [6]. 

Prior Thyroid Surgery or Radiation of the Neck

According to Endocrinologist, Dr. Theodore C. Friedman MD, PhD,  Professor of Medicine at UCLA, primary hypothyroidism can also result from prior thyroid surgery to remove a tumor or nodule, or due to radiation of the neck [6].

Dietary Deficiency

Iodine is essential for thyroid function and in the developing world, the most common type of primary hypothyroidism is related to iodine deficiency. Iodine deficiency is assumed to be rare in the West since iodine is added to salt (iodized salt), in the same way that vitamin D is routinely added to milk.  I have noticed a significant increase in the use of Himalayan pink salt and sea salt for home use in the last decade or so, and wondered how much of the salt being used currently is iodized. Data from 2015 indicates that only 53% of salt sales in the US were iodized [7], so I have to wonder what effect this decreased intake of iodized salt may be having on the prevalence of hypothyroidism. 

Selenium is another mineral that is essential for thyroid function as it functions in the conversion of (inactive) T4 to (active)T3. Like iodine deficiency, selenium deficiency is a significant problem in the developing world, but thought to be rare in the West. Research from 2012 indicates that the selenium content of the soil in the US was already lowest in the major agricultural areas of the Northwest, Northeast, Southeast, and areas of the Midwest near the Great Lakes[8] and at the time, only the Great Plains and the Southwest were reported to have adequate selenium content in the soil [8].

Given the decreased use of iodized salt and decreased presence of selenium in the soil where much of domestic food is grown, I wonder what effect this may be having on formerly rare incidence of nutrient-related hypothyroidism in the US and Canada.

Assessing Thyroid Function – testing for hypothyroidism

Each province in Canada sets its own policy for which laboratory tests are covered by provincial medical plans, and in the US which testing is covered is determined by whether they are performed by in-network or out-of-network labs. 

In British Columbia, thyroid testing covered by the provincial plan is determined by a 2018 document titled Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder [9]. These guidelines outline testing for thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3) and anti-thyroid peroxidase (TPO).

According to the guidelines, risk factors for thyroid disease include [9]:

• men: age ≥ 60 years
• women: age ≥ 50 years
• personal history or strong family history of thyroid disease
• diagnosis of other autoimmune diseases
• past history of neck irradiation
• previous thyroidectomy or radioactive iodine ablation
• drug therapies such as lithium and amiodarone
• dietary factors (iodine excess and iodine deficiency in patients from developing countries)
• certain chromosomal or genetic disorders

Note: Iodine nutrient deficiency for those who are not from developing countries is not included. 

Indications for Testing

1. 1. Routine thyroid function testing is not recommended in asymptomatic patients Testing may be indicated when non-specific symptoms or signs are present in patients who have specific risk factors for thyroid disease.
   2. Testing is indicated for patients with a clinical presentation consistent with thyroid disease as delineated in Table 1: Symptoms and Signs of Thyroid Disease, below.
   3. Where thyroid testing in an asymptomatic patient has occurred and the patient has been diagnosed with subclinical thyroid disease (subclinical hypothyroidism: TSH is elevated in the presence of normal levels of fT4)
   4. If initial testing (i.e. TSH) is normal, repeat testing is unnecessary unless there is a change in clinical condition*.  

The Guidelines (page 3) states, “A TSH value within the laboratory reference interval excludes the majority of cases of primary thyroid dysfunction.

[The reference provided for this is: Jameson, JL., Weetman, A.P.,  Disorders of the Thyroid Gland, Harrison’s Principles of Internal Medicine. 17th ed. New York: McGraw-Hill; 2008. p. 2224–47]

The guide also indicates that “the TSH reference interval will vary depending on the testing laboratory. ” What that means is the cutoff points for an abnormal level of TSH vary between labs in BC.

*What this means is, if TSH lab test results come back in the normal range, no further testing is performed unless the person begins to show some of the accepted hypothyroid signs and symptoms in Table 1, below.

Note: As outlined above, if TSH is found to be normal we know that TSH release from the pituitary gland is normal. There is no testing for the thyroid gland’s response to TSH released from the pituitary gland, it is assumed to be functioning.

Below are the accepted hypothyroid signs and symptoms that warrant testing (from Table 1 [9]).

Only the above list of clinical presentation symptoms is recognized as consistent with hypothyroidism, warranting lab testing.

Looking at the list in Table 1, how many other conditions, including having Covid-19 result in people feeling depressed, having decreased mental function (“brain fog”), feeling physically tired, feeling cold, having reduced degree of movement and muscle weakness, dry flaking skin, and a hoarse voice?  Unless a person has burning or prickling sensation in their hands or feet, or swelling under their eyes, or are sweating less than usual, it is unlikely they would notice anything unusual outside of common flu or Covid symptoms that would have them mention the above to their doctor.

Below is a fuller list of clinical presentation symptoms associated with hypothyroidism, with the ones NOT recognized for testing in italics.

The Guidelines Summarized

Unless you are either a man ≥ 60 years, or a woman ≥ 50 years with a personal history or strong family history of thyroid disease, a diagnosis of other autoimmune diseases, a past history of neck irradiation or previous removal of your thyroid or destruction of your thyroid for medical reason using radioactive iodine, are not on medications such as lithium or amiodarone, and aren’t from a developing country with either iodine excess or iodine deficiency, or have a specific chromosomal or genetic disorder listed, you do not qualify for TSH testing unless you display the specific symptoms listed in Table 1, above).

What if the other common presentations that are NOT also common in colds, flu or Covid-19 were included in the checklist such as;

• • non-pitting edema (swelling) in the lower legs and ankles
  • a puffy swollen face
  • an enlarged tongue (with or without scalloped edges)
  • enlarged saliva glands including under the tongue
  • hair thinning
  • loss of the outer third of eyebrows
  • pale or bluish lips

…would it be more likely that people experiencing these symptoms would go to their doctors, and be tested?

Summary of Assessing Thyroid Function

1. To be diagnosed with hypothyroidism, requires a high TSH and normal or low free free T4 but in many places in Canada and the USA, if TSH is normal, no further testing is done.

2. How one defines “high TSH” is important. In British Columbia, the cutoff points vary between labs, but lab normal values at the labs near me are the normal range is 0.27-0.42 mU/L, but is a result of 3.9 mU/L or 4.0 mU/L really “normal”?

Thyroid Function

TSH                    4.0  (0.27-4.2) mU/L

It is “normal enough” that no further testing is done.

3. Someone can have common clinical manifestations of hypothyroidism (non-pitting edema in the lower legs and ankles, a puffy swollen face, enlarged tongue (with or without scalloped edges), enlarged saliva glands, hair thinning, loss of the outer third of eyebrows or pale or bluish lips but if their symptoms are not on the list in Table 1, they are not eligible for testing of thyroid hormones, fT4 / fT3.

4. Unless a person is from a family with specific risk factors (older age with other autoimmune conditions, or had neck irradiation, a thyroidectomy or radioactive iodine ablation,  or take lithium or amiodarone, or are from a developing country that had iodine excess and iodine deficiency) they are not eligible for testing of thyroid hormones, fT4 / fT3.

Final Thoughts…

If some one has their TSH tested and the results come back in the normal range for that particular lab, no further testing is done — even if they have symptoms documented in the literature to be associated with hypothyroidism. 

My concern is if the definition of who qualifies for fT4 testing may be too narrow,. People with high-normal TSH and symptoms that are associated with hypothyroidism, but not on the “list” in Table 1, will not be tested. Could it be that some people could have greatly improved quality of life if thyroid hormones were evaluated, found to be low, and treatment initiated? [Please see note added July 17, 2022 about a diagnosis of subclinical hypothyroidism where TSH > 4mIU/ with normal T4.]

NOTE, July 16, 2022: It is not the normal TSH test result in the absence of symptoms that I am addressing in this article, but the absence of T4 testing in someone with presenting symptoms of hypothyroidism beyond the official “list”. It is my hope that if someone has those symptoms and a TSH value that is normal, that physicians would remain curious and ask for additional testing.

NOTE: July 17, 2022: I came across an academic paper from 2016 that indicates that diagnosis of subclinical hypothyroidism (SCH) exists in western countries for TSH >4 mIU/L, with normal T4 [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4740939/], whereas the cutoff here for a diagnosis of SCH is >10 mIU/L. (which is based on 2008 reference, as outlined above). Also of interest, another paper I came across from 2016 reported that several previous studies found no significant difference in symptoms between people with  subclinical hypothyroidism  and those with overt hypothyroidism [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4740939/] . The most common symptoms reported of both SCH and overt hypothyroidism were poor memory, slow thinking, muscle cramps, muscle weakness, tiredness, dry skin, feeling colder, hoarse voice, puffy eyes, more constipation.

More Info?

If you have been diagnosed with hypothyroidism and would like to better understand the condition, or would like make sure that you have adequate intake of nutrients known to be important in thyroid health, please send me a note through the Contact Me form and I will reply when I can.

To your good health!

Joy

You can follow me on:

Twitter: https://twitter.com/JoyKiddie
Facebook: https://www.facebook.com/BetterByDesignNutrition/

References

1. Crofts, C., et al., Identifying hyperinsulinaemia in the absence of impaired glucose tolerance: An examination of the Kraft database. Diabetes Res Clin Pract, 2016. 118: p. 50-7.
2. Pareek, M., Bhatt, D.L., Nielsen, M.L., et al,  Enhanced Predictive Capability of a 1-Hour Oral Glucose Tolerance Test: A Prospective Population-Based Cohort Study. Diabetes Care 1 January 2018; 41 (1): 171–177. https://doi.org/10.2337/dc17-1351
3. Bergman M, Chetrit A, Roth J, Dankner R (2016) One-hour post-load plasma glucose level during the OGTT predicts mortality: observations from the Israel Study of Glucose Intolerance, Obesity and Hypertension. Diabet Med 33:1060–1066
4. Hulman, A., Vistisen, D., Glümer, C. et al. Glucose patterns during an oral glucose tolerance test and associations with future diabetes, cardiovascular disease and all-cause mortality rate. Diabetologia 61, 101–107 (2018). https://doi.org/10.1007/s00125-017-4468-z
5. Berkow, R., Beers, M. H., & Fletcher, A. J. (1997). The Merck Manual of Medical Information. Whitehouse Station, N.J.: Merck Research Laboratories.
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