Also a B vitamin, part of the folic acid molecule. Readily available in food and made by bacteria in intestines. Aids in metabolism/utilisation of amino acids. Nourishes hair. (Haas 1999)

Food Sources
Liver, brewers yeast, wheat germ, whole grains, eggs, molasses.


Uncommon, possible with antibiotic use or drugs that alter function of intestinal bacteria. Fatigue, irritability, depression, nervousness, headache, constipation, digestive system problems.

Dosage Range

50 – 100 mg

Main Uses
Used with biotin, pantothenic acid and folic acid for hair. Used in sunscreen, to prevent and treat sunburn. Combined with vitamin E to burns. Vitiligo orally or topically.

High doses irritating to liver – nausea, vomiting, anorexia, fever, skin rash, vitiligo.