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.^(2, 36)

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⁾

NUTRIENT DEFICIENCIES ASSOCIATED WITH HAIR LOSS
VITAMIN/MINERAL	CONDITIONS THAT CAN CAUSE DEFICIENCY	RDA OR SAFE DOSAGE (ADULTS)
ALPHA-LINOLENIC ACID AND LINOLEIC ACID⁽³²⁾	Question: What conditions and diseases might cause fatty acid deficiencies? Answer: The following condiions may cause deficiencies in fatty acids such as alpha-linolenic acid and linoleic acid: Biliary atresia⁽³²⁾ Congenital condition⁽²⁹⁾ Cystic fibrosis⁽³²⁾ Intestinal lymphangiectasia⁽³²⁾ IV feeding (non-supplemented)⁽³²⁾ Short bowel syndrome⁽³²⁾	Question: What is the recommended safe daily dose of alpha linolenic acid and linoleic acid? Answer: The RDA for alpha linolenic acid and linoleic acid is 1.2-2 g/day (dietary sources).⁽⁴⁰⁾
BIOTIN⁽⁵⁾	Question: What conditions and diseases might cause biotin deficiency? Answer: Biotin deficiency can be caused by many factors, including: Antibiotic treatments for infections can kill intestinal bacteria which synthesize biotin.⁽³³⁾ Anticonvulsant medications and epilepsy drugs are linked to biotin deficiency.^(32, 42) Biotinidase deficiency.⁽⁴¹⁾ Consuming excessive amounts of raw egg whites.⁽³²⁾ Conditions that require IV feeding, if non-supplemented, can cause biotin deficiency.⁽³²⁾ Pancreaticoduodenectomy has been linked to biotin deficiency.⁽⁴³⁾ Pregnancy has been linked to biotin deficiency.⁽⁴⁴⁾	Question: What is the recommended safe daily dose of biotin? Answer: The RDA for biotin depends on different factors: 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/day.⁽³⁸⁾ 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⁾
COPPER⁽³²⁾	Question: What conditions and diseases might cause copper deficiency? Answer: Insufficient levels of the trace mineral copper can be caused by several factors, including: HIV⁽³²⁾ IV feeding (non-supplemented)⁽³²⁾ Zinc deficiency or excess zinc (over 30 mg/day)⁽³²⁾	Question: What is the recommended safe daily dose of biotin? Answer: The RDA for copper depends on health status: 0.9 mg/day⁽²⁾ 1.2 mg/day for lactating women⁽²⁾
FOLATE (Folate is also known as folic acid or vitamin B9.)⁽⁴⁶⁾	Question: What conditions and diseases might cause folate deficiency? Answer: Folic acid or folate deficiency can be caused by a number of factors affecting absorption: 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⁾	Question: What is the recommended safe daily dose of folate? Answer: The RDA for folate from food/supplemental sources depends:⁽⁴⁶⁾ 400 mcg/day adults 600 mcg/day for pregnant women 500 mcg/day for lactating women To treat severe deficiency, 1-5 mg/day
IRON⁽³²⁾ (Insufficient iron can range from iron deficiency to the more serious condition anemia.)⁽³²⁾	Question: What conditions and diseases might cause iron deficiency? Answer: Insufficient iron is fairly common in adolescent girls and premenopausal women.⁽³²⁾ Factors causing iron deficiency include: Common in adolescent girls and premenopausal women⁽³²⁾ Excessive menstruation⁽²⁹⁾ Gastrointestinal bleeding⁽³²⁾ Lactation⁽³²⁾ Pregnancy⁽³²⁾ Vegetarian or vegan diet⁽²⁹⁾	Question: What is the recommended safe daily dose of iron? Answer: The RDA for iron from food/supplemental sources depends on different factors: 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 effects.⁽²⁹⁾ The amino acid lysine helps increase uptake of iron.⁽⁴⁷⁾
L-CYSTINE⁽²⁾	Question: What conditions and diseases might cause L-cystine deficiency? Answer: Several factors can lead to L-cystine deficiency: Chronic insufficient protein consumption⁽²⁹⁾ HIV⁽³²⁾ Severe calorie restriction⁽²⁹⁾	Question: What is the recommended safe daily dose of L-cystine? Answer: The RDA for iron from food/supplemental sources is 100 mg/day⁽²⁾
NIACIN AND NIACINAMIDE (Niacin and niacinamide are also known as vitamin B3 complex.)^(10, 32) (Niacin deficiency is a condition called pellagra.)	Question: What conditions and diseases might cause niacin or niacinamide deficiency? Answer: Vitamin B3 deficiency can be caused by many different factors, including: 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⁾	Question: What is the recommended safe daily dose of niacin? Answer: The minimum RDA for vitamin B3 complex is 13 mg/daily^(10, 32)
PANTOTHENIC ACID⁽⁴⁷⁾ (Vitamin B5)	Question: What conditions and diseases might cause pantothenic acid deficiency? Answer: Insufficient pantothenic acid can be caused by: Intestinal malabsorption⁽⁵⁰⁾ Severe malnutrition⁽⁵⁰⁾	Question: What is the recommended safe daily dose of pantothenic acid? Answer: The RDA for pantothenic acid is 5-10 mg/day. Pantothenic acid can also be applied topically as a 2% cream.⁽⁵¹⁾
SELENIUM⁽³²⁾	Question: What conditions and diseases might cause selenium deficiency? Answer: A variety of factors can cause selenium deficiency: Anticonvulsant medications⁽²⁹⁾ Dietary deficiency (especially in areas where the soil levels are low in selenium)⁽³²⁾ HIV⁽³²⁾ IV feeding (non-supplemented)⁽³²⁾	Question: What is the recommended safe daily dose of selenium? Answer: The recommended dose for selenium is 100 mcg/day if deficient⁽³⁵⁾ However, excessive selenium intake is associated with hair loss.⁽⁵²⁾
THIAMINE (Thiamine is also known as vitamin B1 and can also be spelled as thiamin.) (Thiamine deficiency is a condition called beriberi and is known to cause thinning hair.)⁽¹⁰⁾	Question: What conditions and diseases might cause thiamine deficiency? Answer: Thiamine deficiency can be caused by a variety of factors, including: Chronic alcohol abuse⁽⁵³⁾ Diabetes⁽⁴⁸⁾ Extreme malnutrition⁽¹⁰⁾ Gastrointestinal disease⁽⁴⁸⁾ Habitual consumption of raw shellfish and raw freshwater fish⁽⁵³⁾ HIV⁽⁵³⁾ Insufficient dietary intake; diets high in rice but low in thiamin (frequently associated with low incomes)^(48, 53) Kidney failure requiring hemodialysis⁽⁵³⁾ Lactation⁽⁵³⁾ Large amounts of coffee and tea⁽⁵³⁾ Malaria⁽⁵³⁾ Pregnancy⁽⁵³⁾ Seasonal ataxia⁽⁵³⁾	Question: What is the recommended safe daily dose of thiamine? Answer: RDA for thiamine depends on gender, age, and health status:⁽⁵³⁾ 1.2 mg/day for men 1.1 mg/day for women 1.4 mg/day for pregnant and lactating women 1.5 mg/day for the elderly
VITAMIN A ²⁹⁾	Question: What conditions and diseases might cause vitamin A deficiency? Answer: Vitamin A deficiency can be caused by several diseases or lifestyle factors: Celiac disease⁽²⁹⁾ Crohn's disease⁽²⁹⁾ Excess alcohol consumption⁽²⁹⁾ Pancreatic disease⁽²⁹⁾	Question: What is the recommended safe daily dose of vitamin A? Answer: The RDA for vitamin A is under 10,000 IU/day (including pregnant or lactating women).⁽²⁹⁾ Caution: Taking 10,000 IU/day or more of vitamin A daily can cause hair loss.⁽²⁹⁾
VITAMIN B6^(38, 54)	Question: What conditions and diseases might cause vitamin B6 deficiency? Answer: Vitamin B6 deficiency can be caused by several factors: Hyperthyroidism⁽⁵⁴⁾ Kidney failure that leads to uremia^(48, 55) Liver disease⁽⁴⁸⁾ Other vitamin deficiencies⁽⁴⁸⁾	Question: What is the recommended safe daily dose of vitamin B6? Answer: RDA for vitamine B6 depends on gender, age, and health status:⁽⁵⁴⁾ 1.3 mg/day for men under age 50 1.7 mg/day for men over age 50 1.3 mg/day for premenopausal women 1.5 mg/day for postmenopausal women 1.9 mg/day for pregnant women 2 mg/day for lactating women
VITAMIN B12 (Vitamin B12 is also known as cobalamin.) (Vitamin B12 deficiency can cause a condition called pernicious anemia.)⁽³²⁾	Question: What conditions and diseases might cause vitamin B12 deficiency? Answer: Vitamin B12 deficiency can be caused by a number of factors, including conditions that affect absorption: 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⁾	Question: What is the recommended safe daily dose of vitamin B12? Answer: The RDA for vitamin B12 is 3 mg/day.⁽³²⁾ Vitamin B12 is best taken sublingually for those with digestive problems and difficulties absorbing vitamin B12.⁽³⁷⁾
VITAMIN C (Deficiency in vitamin C is a condition called scurvy.)⁽³²⁾	Question: What conditions and diseases might cause vitamin C deficiency? Answer: Several factors can lead to vitamin C deficiency: Alcoholism⁽³²⁾ Cancer ³² Chronic renal failure⁽³²⁾	Question: What is the recommended safe daily dose of vitamin C? Answer: The RDA for vitamin C is 300-1000 mg/day.⁽³²⁾
VITAMIN D3⁽²⁹⁾	Question: What conditions and diseases might cause vitamin D3 deficiency? Answer: Factors leading to vitamin D deficiency include: Increased age⁽²⁹⁾ Poor/restricted diets⁽²⁹⁾	Question: What is the recommended safe daily dose of vitamin D? Answer: The RDA for vitamin D3 is 400 IU/day for adults (including pregnant women).⁽²⁹⁾
ZINC⁽³²⁾	Question: What conditions and diseases might cause zinc deficiency? Answer: Zinc deficiency can be caused by a number of different conditions, diseases, drugs, and lifestyle factors: ACE inhibitor drugs⁽³²⁾ Acrodermatitis enteropathica⁽³²⁾ Alcoholism⁽³²⁾ Anorexia nervosa⁽³²⁾ Chronic colitis⁽²⁹⁾ Excessive iron⁽²⁹⁾ Gastrointestinal bypass surgery⁽³²⁾ Hemodialysis⁽⁵⁰⁾ HIV⁽³²⁾ Kidney disease⁽³²⁾ Lactation⁽²⁹⁾ Nephropathy⁽²⁹⁾ Pancreatitis⁽³²⁾ Sickle cell anemia⁽⁵⁰⁾ Vitamin A deficiency⁽²⁹⁾	Question: What is the recommended safe daily dose of zinc? Answer: RDA for zinc depends on gender, age, and health status: 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 zinc.⁽⁴⁷⁾

NUTRIENT DEFICIENCIES ASSOCIATED WITH HAIR LOSS

VITAMIN/MINERAL

CONDITIONS THAT CAN CAUSE DEFICIENCY

RDA OR
SAFE DOSAGE (ADULTS)

ALPHA-LINOLENIC ACID AND
LINOLEIC ACID⁽³²⁾

Question: What conditions and diseases might cause fatty acid deficiencies?

Answer: The following condiions may cause deficiencies in fatty acids such as alpha-linolenic acid and linoleic acid:

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

Question: What is the recommended safe daily dose of alpha linolenic acid and linoleic acid?

Answer: The RDA for alpha linolenic acid and linoleic acid is 1.2-2 g/day (dietary sources).⁽⁴⁰⁾

BIOTIN⁽⁵⁾

Question: What conditions and diseases might cause biotin deficiency?

Answer: Biotin deficiency can be caused by many factors, including:

Antibiotic treatments for infections can kill intestinal bacteria which synthesize biotin.⁽³³⁾
Anticonvulsant medications and epilepsy drugs are linked to biotin deficiency.^(32, 42)
Biotinidase deficiency.⁽⁴¹⁾
Consuming excessive amounts of raw egg whites.⁽³²⁾
Conditions that require IV feeding, if non-supplemented, can cause biotin deficiency.⁽³²⁾
Pancreaticoduodenectomy has been linked to biotin deficiency.⁽⁴³⁾
Pregnancy has been linked to biotin deficiency.⁽⁴⁴⁾

Question: What is the recommended safe daily dose of biotin?

Answer: The RDA for biotin depends on different factors:

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/day.⁽³⁸⁾

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⁾

COPPER⁽³²⁾

Question: What conditions and diseases might cause copper deficiency?

Answer: Insufficient levels of the trace mineral copper can be caused by several factors, including:

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

Question: What is the recommended safe daily dose of biotin?

Answer: The RDA for copper depends on health status:

0.9 mg/day⁽²⁾
1.2 mg/day for lactating women⁽²⁾

FOLATE
(Folate is also known as folic acid or vitamin B9.)⁽⁴⁶⁾

Question: What conditions and diseases might cause folate deficiency?

Answer: Folic acid or folate deficiency can be caused by a number of factors affecting absorption:

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⁾

Question: What is the recommended safe daily dose of folate?

Answer: The RDA for folate from food/supplemental sources depends:⁽⁴⁶⁾

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

IRON⁽³²⁾
(Insufficient iron can range from iron deficiency to the more serious condition anemia.)⁽³²⁾

Question: What conditions and diseases might cause iron deficiency?

Answer: Insufficient iron is fairly common in adolescent girls and premenopausal women.⁽³²⁾

Factors causing iron deficiency include:

Common in adolescent girls and premenopausal women⁽³²⁾
Excessive menstruation⁽²⁹⁾
Gastrointestinal bleeding⁽³²⁾
Lactation⁽³²⁾
Pregnancy⁽³²⁾
Vegetarian or vegan diet⁽²⁹⁾

Question: What is the recommended safe daily dose of iron?

Answer: The RDA for iron from food/supplemental sources depends on different factors:

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 effects.⁽²⁹⁾

The amino acid lysine helps increase uptake of iron.⁽⁴⁷⁾

L-CYSTINE⁽²⁾

Question: What conditions and diseases might cause L-cystine deficiency?

Answer: Several factors can lead to L-cystine deficiency:

Chronic insufficient protein consumption⁽²⁹⁾
HIV⁽³²⁾
Severe calorie restriction⁽²⁹⁾

Question: What is the recommended safe daily dose of L-cystine?

Answer: The RDA for iron from food/supplemental sources is 100 mg/day⁽²⁾

NIACIN AND
NIACINAMIDE

(Niacin and niacinamide are also known as vitamin B3 complex.)^(10, 32)
(Niacin deficiency is a condition called pellagra.)

Question: What conditions and diseases might cause niacin or niacinamide deficiency?

Answer: Vitamin B3 deficiency can be caused by many different factors, including:

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⁾

Question: What is the recommended safe daily dose of niacin?

Answer: The minimum RDA for vitamin B3 complex is 13 mg/daily^(10, 32)

PANTOTHENIC ACID⁽⁴⁷⁾
(Vitamin B5)

Question: What conditions and diseases might cause pantothenic acid deficiency?

Answer: Insufficient pantothenic acid can be caused by:

Intestinal malabsorption⁽⁵⁰⁾
Severe malnutrition⁽⁵⁰⁾

Question: What is the recommended safe daily dose of pantothenic acid?

Answer: The RDA for pantothenic acid is 5-10 mg/day. Pantothenic acid can also be applied topically as a 2% cream.⁽⁵¹⁾

SELENIUM⁽³²⁾

Question: What conditions and diseases might cause selenium deficiency?

Answer: A variety of factors can cause selenium deficiency:

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

Question: What is the recommended safe daily dose of selenium?

Answer: The recommended dose for selenium is 100 mcg/day if deficient⁽³⁵⁾

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

THIAMINE
(Thiamine is also known as vitamin B1 and can also be spelled as thiamin.)

(Thiamine deficiency is a condition called beriberi and is known to cause thinning hair.)⁽¹⁰⁾

Question: What conditions and diseases might cause thiamine deficiency?

Answer: Thiamine deficiency can be caused by a variety of factors, including:

Chronic alcohol abuse⁽⁵³⁾
Diabetes⁽⁴⁸⁾
Extreme malnutrition⁽¹⁰⁾
Gastrointestinal disease⁽⁴⁸⁾
Habitual consumption of raw shellfish and raw freshwater fish⁽⁵³⁾
HIV⁽⁵³⁾
Insufficient dietary intake; diets high in rice but low in thiamin (frequently associated with low incomes)^(48, 53)
Kidney failure requiring hemodialysis⁽⁵³⁾
Lactation⁽⁵³⁾
Large amounts of coffee and tea⁽⁵³⁾
Malaria⁽⁵³⁾
Pregnancy⁽⁵³⁾
Seasonal ataxia⁽⁵³⁾

Question: What is the recommended safe daily dose of thiamine?

Answer: RDA for thiamine depends on gender, age, and health status:⁽⁵³⁾

1.2 mg/day for men
1.1 mg/day for women
1.4 mg/day for pregnant and lactating women

1.5 mg/day for the elderly

VITAMIN A ²⁹⁾

Question: What conditions and diseases might cause vitamin A deficiency?

Answer: Vitamin A deficiency can be caused by several diseases or lifestyle factors:

Celiac disease⁽²⁹⁾
Crohn's disease⁽²⁹⁾
Excess alcohol consumption⁽²⁹⁾
Pancreatic disease⁽²⁹⁾

Question: What is the recommended safe daily dose of vitamin A?

Answer: The RDA for vitamin A is under 10,000 IU/day (including pregnant or lactating women).⁽²⁹⁾

Caution: Taking 10,000 IU/day or more of vitamin A daily can cause hair loss.⁽²⁹⁾

VITAMIN B6^(38, 54)

Question: What conditions and diseases might cause vitamin B6 deficiency?

Answer: Vitamin B6 deficiency can be caused by several factors:

Hyperthyroidism⁽⁵⁴⁾
Kidney failure that leads to uremia^(48, 55)
Liver disease⁽⁴⁸⁾
Other vitamin deficiencies⁽⁴⁸⁾

Question: What is the recommended safe daily dose of vitamin B6?

Answer: RDA for vitamine B6 depends on gender, age, and health status:⁽⁵⁴⁾

1.3 mg/day for men under age 50
1.7 mg/day for men over age 50
1.3 mg/day for premenopausal women
1.5 mg/day for postmenopausal women
1.9 mg/day for pregnant women
2 mg/day for lactating women

VITAMIN B12
(Vitamin B12 is also known as cobalamin.)
(Vitamin B12 deficiency can cause a condition called pernicious anemia.)⁽³²⁾

Question: What conditions and diseases might cause vitamin B12 deficiency?

Answer: Vitamin B12 deficiency can be caused by a number of factors, including conditions that affect absorption:

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⁾

Question: What is the recommended safe daily dose of vitamin B12?

Answer: The RDA for vitamin B12 is 3 mg/day.⁽³²⁾

Vitamin B12 is best taken sublingually for those with digestive problems and difficulties absorbing vitamin B12.⁽³⁷⁾

VITAMIN C
(Deficiency in vitamin C is a condition called scurvy.)⁽³²⁾

Question: What conditions and diseases might cause vitamin C deficiency?

Answer: Several factors can lead to vitamin C deficiency:

Alcoholism⁽³²⁾
Cancer ³²
Chronic renal failure⁽³²⁾

Question: What is the recommended safe daily dose of vitamin C?

Answer: The RDA for vitamin C is 300-1000 mg/day.⁽³²⁾

VITAMIN D3⁽²⁹⁾

Question: What conditions and diseases might cause vitamin D3 deficiency?

Answer: Factors leading to vitamin D deficiency include:

Increased age⁽²⁹⁾
Poor/restricted diets⁽²⁹⁾

Question: What is the recommended safe daily dose of vitamin D?

Answer: The RDA for vitamin D3 is 400 IU/day for adults (including pregnant women).⁽²⁹⁾

ZINC⁽³²⁾

Question: What conditions and diseases might cause zinc deficiency?

Answer: Zinc deficiency can be caused by a number of different conditions, diseases, drugs, and lifestyle factors:

ACE inhibitor drugs⁽³²⁾
Acrodermatitis enteropathica⁽³²⁾
Alcoholism⁽³²⁾
Anorexia nervosa⁽³²⁾
Chronic colitis⁽²⁹⁾
Excessive iron⁽²⁹⁾
Gastrointestinal bypass surgery⁽³²⁾
Hemodialysis⁽⁵⁰⁾
HIV⁽³²⁾
Kidney disease⁽³²⁾
Lactation⁽²⁹⁾
Nephropathy⁽²⁹⁾
Pancreatitis⁽³²⁾
Sickle cell anemia⁽⁵⁰⁾
Vitamin A deficiency⁽²⁹⁾

Question: What is the recommended safe daily dose of zinc?

Answer: RDA for zinc depends on gender, age, and health status:

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 zinc.⁽⁴⁷⁾

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. ^32, 49

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.

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