Information and Solutions for Men and Women

Nutrient Deficiencies Linked to Hair Loss

A surprising number of vitamin deficiencies may cause hair loss.

In general, hair needs adequate amounts of protein, essential fats, and other nutrients to stay healthy. Just like any other part of your body, diet deficiencies can have a negative impact and contribute to hair thinning or loss. In fact, recent advances in chemical analysis tools, combined with the ideal structure of hair, suggest that hair can reveal a person’s nutritional and health history. Studies have already shown that hair proteins reflect dietary protein sources and internal metabolic processes by identifiable effects on the proteins. 236

Other than simply not eating enough, other factors that can affect proper nutrition and hair health include: 32

  • Medical conditions that cause poor absorption of nutrients (e.g., cancer, gastrointestinal disorders, and chronic renal failure).
  • Illness that increases nutrient requirements (e.g., thyroid, heart, and lung diseases).
  • Poor diet choices.
  • Inadequate protein intake.
  • Medication that affects how nutrients are absorbed and metabolized.

Increased Risk of Malnourishment with Age

Essential nutrients may become even more of a factor in hair loss as we age. Studies suggest that even in a comparatively wealthy, industrialized country like the United States up to 50% of the elderly population do not take in the recommended amounts of nutrients on a daily basis, and up to 30% have below normal levels systemically. In addition to the factors mentioned above, age-related issues also help explain why malnourishment is particularly prevalent in older people: 32

  • Naturally reduced appetite seen in the elderly—probably due to hormonal and neurotransmitter changes, as well as decreased sense of smell and taste.
  • Inadequate income leads to skipped or poor-quality meals.
  • Social isolation can lead to depression and apathy about food.
  • Physical and cognitive impairments.

Because hair follicles are composed of highly active cells, they are naturally more sensitive to nutritional deficiencies. Inadequate intake and absorption of essential vitamins, minerals, amino acids, and other trace elements not only slows down the growth of healthy hair, it contributes to hair loss and greying of the hair. 32

Deficiencies in certain specific nutrients are known to cause or are associated with hair loss. Even in developed countries, where nutritional deficiency is relatively rare or unknown for certain nutrients, evidence is mounting that many people have marginal deficiencies. Studies support the use of supplements to help prevent or improve hair loss. 37-39

These marginal nutrient deficiencies can contribute to hair loss. For example, although iron deficiency is defined by ferritin levels in the blood as below 40 ng/mL (which triggers follicles to move into telogen phase), levels between 40 and 70 ng/mL are associated with excess telogen hair. 30


  • Biliary atresia 32
  • Congenital condition 29
  • Cystic fibrosis 32
  • Intestinal lymphangiectasia 32
  • IV feeding (non-supplemented) 32
  • Short bowel syndrome 32

1.2-2 g/day (dietary sources) 40


3-5 mg/day recommended if experiencing hair loss 29

Patients with clear biotin deficiency have been treated with doses ranging between 60 and 1000 mcg/day38

Animal studies show that biotin supplementation counteracts the side effects of anticonvulsants. 33

Sources such as milk, tuna, yogurt, cauliflower, green beans, and spinach are not particularly rich in biotin as commonly reported, based on rigorous analysis. However, the good news is that there still are plenty of foods rich in biotin. 45

  • HIV 32
  • IV feeding (non-supplemented) 32
  • Zinc deficiency or excess (over 30 mg/day) 32

0.9 mg/day 2

1.2 mg/day for lactating women 2


(Folic Acid, Vitamin B9) 46
  • Alcoholism 46
  • Celiac disease 46
  • Drug induced (e.g., barbiturates, methotrexate, nitrofurantoin, oral contraceptives, phenytoin, primidone) 46
  • Intestinal malabsorption 46
  • Liver disease 46
  • Renal dialysis 46
  • Ulcerative colitis 46
  • Vitamin B12 deficiency 38

RDA from food/supplemental sources: 46

  • 400 mcg/day adults
  • 600 mcg/day for pregnant women
  • 500 mcg/day for lactating women
  • 250-1000 mcg/day
  • To treat severe deficiency, 1-5 mg/day

(ranging from deficiency to anemia) 32
  • Common in adolescent girls and premenopausal women 32
  • Excessive menstruation 29
  • Gastrointestinal bleeding 32
  • Lactation 32
  • Pregnancy 32
  • Vegetarian or vegan diet 29

18 mg/day for premenopausal women 5

27 mg/day for pregnant women 5

9 mg/day for lactating women 5

Do not take more than 45 mg/day because of potential adverse side effects29

The amino acid lysine helps increase uptake of iron. 47

  • Chronic insufficient protein consumption 29
  • HIV 32
  • Severe calorie restriction 29

100 mg/day 2


(Vitamin B3 complex) 10, 32

(a condition called pellagra)
  • Alcoholism 32
  • Anorexia nervosa 32
  • Carcinoid tumors 32
  • Crohn’s disease 32
  • Hartnup disease 48
  • HIV 49
  • Inflammatory bowel disease 10
  • Insufficient dietary intake in areas where corn is a main food source 10
  • Long-term antibiotic therapy 10
  • Medications (i.e., isoniazid and 5-fluoruracil) 10, 32
  • Renal insufficiency and dialysis 10

Minimum RDA of 13 mg/daily 10, 32


(Vitamin B5)
  • Intestinal malabsorption 50
  • Severe malnutrition 50

5-10 mg/day 51

2% cream 51

  • Anticonvulsant medications 29
  • Dietary deficiency (especially in areas where the soil levels are low in selenium) 32
  • HIV 32
  • IV feeding (non-supplemented) 32

100 mcg/day if deficient 35

However, excessive selenium intake is associated with hair loss. 52


(Vitamin B1; thiamin)

(a condition called beriberi which causes thin hair) 10

1.2 mg/day for men 53

1.1 mg/day for women 53

1.4 mg/day for pregnant and lactating women 53

1.5 mg/day for the elderly 53

  • Celiac disease 29
  • Crohn’s disease 29
  • Excess alcohol consumption 29
  • Pancreatic disease 29

Under 10,000 IU/day (including pregnant or lactating women); more than this can cause hair loss 29

VITAMIN B6 38, 54

1.3 mg/day for men under age 50 54

1.7 mg/day for men over age 50 54

1.3 mg/day for premenopausal women 54

1.5 mg/day for postmenopausal women 54

1.9 mg/day for pregnant women 54

2 mg/day for lactating women 54



(can cause a condition called pernicious anemia) 32
  • Atrophic gastritis 32
  • Celiac disease 32
  • Digestive disorders 37
  • Fish tapeworm (an ingested parasite) 32
  • Lack of intrinsic factor, a protein in the gastrointestinal tract needed to absorb vitamin B12 37
  • Malabsorption (common in older people) 37
  • Pancreatic disease (certain forms) 32
  • Stagnant bowel syndrome 32
  • Strict vegetarianism 32

3 mg/day 32

Best taken sublingually for those with digestive problems and difficulties absorbing vitamin B1237


(a condition called scurvy) 32
  • Alcoholism 32
  • Cancer 32
  • Chronic renal failure 32

300-1000 mg/day 32

  • Increased age 29
  • Poor/restricted diets 29

400 IU/day for adults (including pregnant women) 29


8-10 mg/day 32

15 mg/day—lactating women 29

25-50 mg/day to treat deficiency 29

The amino acid lysine helps increase uptake of zinc47

Such as alpha-linolenic acid. 32
Hair proteins are resistant to degradation once formed. 36
Also known as omega-3 fatty acids. 40
Such carbamazepine, phenobarbital, phenytoin, and primadone. 32
The enzyme needed to release biotin from protein it is bound to when consumed. 41
Egg whites have a substance in the them (avidin) that binds biotin. 32
Equivalent to one milligram.
Valproic acid. 42
Surgery that removes parts of the pancreas, stomach, and small intestine and impedes absorption of biotin and zinc. 43
Human immunodeficiency virus.
A condition called menorrhagia. 29
Too much iron can increase free radicals and destroy vitamin E; it can also may cause heart disease and is possibly carcinogenic. 5
Human immunodeficiency virus.
Also known as nicotinic acid. 49
Also called nicotinamide. 48
Note: Some experts suggest that niacinamide be used for vitamin B3 supplementation because excess niacin may have adverse side effects. 10
Human immunodeficiency virus.
The niacin in corn is bound and cannot be digested enough for use. 10
INH drugs that block metabolism of niacin from tryptophan, typically a substantial source of niacin.
Human immunodeficiency virus. 3249
Certain species contain thiaminase enzymes that breakdown thiamin (which but are normally inactivated with heat from cooking). 53
Human immunodeficiency virus.
These contain anti-thiamin factors. 53
Neurological syndrome from consumption of African silkworms. 53
Moderate degree of deficiency increases sensitivity to even low levels of androgens and also affects amino acid metabolism. 32
Accumulation of water and waste products; can be fatal if untreated. 55
Dissolved under the tongue. 32
Impair zinc absorption. 32
A rare genetic disorder in children. 32
Human immunodeficiency virus.
Disclaimer: This website is not intended to replace professional consultation, diagnosis, or treatment by a licensed physician. If you require any medical related advice, contact your physician promptly. Information presented on this website is exclusively of a general reference nature. Do not disregard medical advice or delay treatment as a result of accessing information at this site.