Vitamin Bs, Folate and Biotin

RDA: 1.1 mg (1100 mcg)

Roles of vitamin B1 in the body: Vitamin B1 is a co-enzyme that helps release energy from carbohydrate by converting it into glucose. Vitamin B1 also:

• Stimulates appetite
• Keeps nerve cells healthy
• Maintains muscle tone

Deficiency: Beriberi (loss of appetite, fatigue, nerve and muscle degeneration, mental confusion, staggering gait, heart failure, fluid retention) and Wernicke-Korsakoff syndrome (double vision, faulty memory, abnormal behavior) are both diseases that result from Vitamin B1 deficiency.

Vitamin B1 deficiency is more common in alcoholics, malnourished infants and elderly persons. Alcohol interferes with thiamin absorption, storage and conversion into its active form. Alcoholics require large doses to combat effects (10-100mg).

Toxicity: None reported to date.

Good food sources of vitamin B1: Whole grain cereals, dried beans, nuts, pork, liver, fish, bran, enriched rice, brewer's yeast and fresh green leafy vegetables are all good sources of vitamin B1.

RDA: 1.7 mg (1700 mcg)

Roles of vitamin B2 in the body:

• Necessary for protein, fat and carbohydrate metabolism
• Helps with growth
• Keeps skin healthy

Deficiency: Symptoms of vitamin B2 deficiency include: inflammation of mouth and tongue; cracking/dryness of lips; lack of growth in children.

Good food sources of vitamin B2: Milk, enriched soy drinks, liver, eggs, dark green vegetables, cheese, lean meat, enriched cereals, nuts and brewer's yeast are all good sources of vitamin B2.

RDA: 20 mg (Children: 12-15mg)

Roles of vitamin B3 in the body

• Important for continual supply of energy to all cells
• Involved in metabolism of carbohydrates, protein and fats
• Maintains normal functioning of skin, nerves and digestive tract
• Enhances immune system

Deficiency: Symptoms of vitamin B3 deficiency include diarrhea, dermatitis, dementia, and soreness and ulceration of mouth corners.

Toxicity: High supplemental dosages (1-4 grams) used as a drug to lower blood cholesterol can cause nausea and skin flushing.

Good food sources of Vitamin B3: Fish, meats, liver, poultry, dried beans, nuts, yeast, Vegemite, wholegrain cereals are all good sources of vitamin B3
 

RDA: Not yet established. 4-7 mg daily considered adequate and safe.

Roles of vitamin B5 in the body: Vitamin B5 is primarily involved in the metabolism of carbohydrates, fats, and protein.

Deficiency: Deficiency is rare. Malaise and vomiting are symptoms of deficiency.

Good food sources of vitamin B5: Vitamin B5 is found in a wide variety of foods. Highest amounts are found in meats, liver, kidney, yeast, fish, wholegrain cereals, dried beans, nuts, eggs and royal jelly of queen bees. Vegetables have moderate amounts. Most fruits have small amounts.

RDA: 1.9 mg

Roles of vitamin B6 in the body:

• Essential for metabolism of amino acids and protein
• Important for brain function
• Helps formation and growth of red blood cells
• Helps produce antibodies to combat allergens
• Enhances immune system
• Supplemental doses may help relieve PMT symptoms
• Lessens symptoms of carpal tunnel syndrome
• Helps correct metabolic imbalances caused by oral contraceptives

Deficiency: Vitamin B6 deficiency can lead to anemia, irritability, weakness, insomnia, nervousness and skin problems.

Toxicity: Vitamin B6 toxicity is low - up to 50 mg/day may be taken. However, megadoses (2000 mg/day) may cause serious nerve damage (numbness in feet or hands, unsteady on feet).

Good food sources of vitamin B6: Vitamin B6 is widespread in foods. Meats, liver, kidney, egg yolk, wholegrain cereals, beans, yeast, and soy drinks all contain vitamin B6.

RDA: 2 mcg (Children 1.5 mcg; Adults 2 mcg; Pregnancy 3 mcg; Lactating 2.5 mcg)

Roles of vitamin B12 in the body

• Essential for regeneration of red blood cells
• Helps make DNA and hemoglobin
• Maintains nerve health and mental abilities

Deficiency: Vitamin B12 deficiency causes Pernicious anemia; symptoms of the disease include fatigue, pale yellow skin, anorexia, weight loss, apathy and depression. Glossitis (smooth red tongue) is also a symptom of vitamin B12 deficiency.

Correction of marginal deficiencies may have speed up recovery from illness or surgery and alleviate symptoms due to neurological damage or deterioration of mental functioning. (B12 deficiency is sometimes misdiagnosed as Alzheimer's.)

Vitamin B12 deficiency is more common in elderly people, breast-fed babies of vegan mothers, and vegans. It may not show up for some time because the body can store sufficient B12 for two to three years.

Toxicity: No evidence of toxicity.

Good food sources of vitamin B12: Vitamin B12 is present in meat, liver, eggs, dairy products, fish and soy drinks. There are negligible amounts in vegetables, grains, brewer's yeast, soy products (tofu, miso, tempeh and tamari). Cooking does not usually diminish vitamin B12 content, although alcohol can interfere with B12 absorption.

RDA: Not yet developed. 100-200 mcg/day is considered adequate and safe.

Roles of biotin in the body

• A coenzyme required for fatty acid synthesis
• Also helps metabolize amino acids and carbohydrate
• Helps maintain healthy skin, hair and a balanced hormonal system

Deficiency: Biotin deficiency is rare but can develop from excessive daily intake of over 12 raw egg whites (which contains a protein, avidin, that binds biotin and prevents its absorption; avidin is destroyed by cooking).

Symptoms include dermatitis, glossitis, lethargy, muscle pains, nausea.

Good food sources of biotin: Intestinal bacteria provide most of our biotin requirements, but biotin is also present in a variety of foods. Best sources include egg yolks, liver, yeast, nuts, milk, fresh vegetables.

RDA: 200 mcg (Pregnancy - 400 mcg, Lactation - 300 mcg)

Roles of folate in the body:

• Acts with B12 in producing hemoglobin for red blood cells
• Essential for synthesis of protein and DNA in newly forming cells
• May protect against colon cancer (by guarding integrity of genetic messages encoded in DNA)

Deficiency: Anemia is an early sign of folate deficiency. Deficiency is more common in pregnant women, the elderly and alcoholics.

Deficiency in pregnant women increases the risk of Spina Bifida (spinal cord does not form properly) in the growing fetus. The risk is reduced by taking a low dose supplement (400 mcg) before and during early months of pregnancy (since defect occurs by sixth week of pregnancy).

Deficiency also increases risk of cervical cancer.  

Good food sources of folate: Fresh leafy, green vegetables are the best sources of folate.