Patients faced with hair loss need to be screened by medical history, dietary history, and a physical exam for risk factors to assess nutrient deficiency.
Patients with nutritional deficiencies do require nutrient supplementation. Few supplements carry the risk of worsening hair loss or even the risk of toxicity.
Patients with hair loss often inquire whether nutritional supplements can help restore hair growth or prevent further hair loss. Several people do go in for dietary supplements without consulting a dietician, hoping that the supplements will help.
Hair loss is common in both men and women affected by pattern hair loss by age 50. Several nutritional supplements are marketed as hair loss treatments.
Over-supplementation of certain nutrients, including selenium, vitamin A, and vitamin E, has been linked to hair loss. There is a lack of literature regarding the effects of supplementation on individuals without nutrient deficiencies.
Iron deficiency (ID) happens to be the world’s most common nutritional deficiency and a well-known cause of hair loss. Certain populations seem to be at higher risk for ID, and a medical and dietary history can reveal risk factors. Pre-menopausal women are, of course, at higher risk due to menstrual blood loss, while postmenopausal women and men can be at higher risk due to gastrointestinal blood loss. Other risk factors include malabsorption disorders (such as celiac disease) as well as achlorhydria or the use of H2 blockers, as iron does require an acidic pH for absorption.
Vegans and vegetarians are also at greater risk of ID.
Zinc is no doubt an essential mineral required by hundreds of enzymes and multiple transcription factors that tend to regulate gene expression.
Zinc deficiency can be either inherited or acquired and may also affect multiple organ systems. Patients can experience diarrhea, immunological effects, and delayed wound healing. Abnormalities in taste and smell can occur.
Dietary risk factors do include vegetarianism, as the bioavailability of zinc is lower in vegetables than meat. Also, vegetarians consume more legumes and whole grains, which contain phytates that bind to zinc and inhibit absorption. Zinc toxicity can rather occur with excess supplementation.
Pellagra, due to a deficiency of niacin, does result in the well-known triad of photosensitive dermatitis, diarrhea, and dementia. Alopecia is considered to be another frequent clinical finding.
Pellagra became rare in several developed countries after niacin fortification of food was introduced. Alcoholism is, in fact, now considered the most common cause of pellagra in developed countries. Other causes include malabsorption disorders or even drug-induced cases, like isoniazid.
Deficiency of the polyunsaturated essential fatty acids linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid) can, of course, result from inappropriate parenteral nutrition as well as malabsorption disorders such as cystic fibrosis. Hair changes do include loss of scalp hair and eyebrows, as well as lightening of hair. Unsaturated fatty acids may modulate androgen action by inhibiting 5α-reductase, similar to the drug finasteride. At the same time, arachidonic acid, an omega-6 fatty acid, can promote hair growth by enhancing follicle proliferation.
Limited information is here regarding supplementation.
Selenium helps protect against oxidative damage as well as hair follicle morphogenesis. Risk factors for deficiency include living in areas with low selenium soil content (particularly in parts of China, Tibet, and also Siberia), long-term hemodialysis, HIV, as well as malabsorption disorders.
Due to a lack of human research, few hair loss supplements are marketed as containing selenium.
Vitamin D aids in hair follicle cycling. Risk factors related to vitamin D deficiency include inadequate sun exposure, dark skin, obesity, gastric bypass, and fat malabsorption.
Vitamin A happens to be a group of compounds including retinol, retinal, retinoic acid, and also pro-vitamin A carotenoids. Dietary vitamin A appears to activate hair follicle stem cells, although its role is recognized as complex, and proper levels of retinoic acid are required for optimal function of the hair follicle.
Nutrition is required to prevent hair loss.