Vitamin B7, also known as biotin and sometimes referred to as Vitamin H, is a water-soluble vitamin belonging to the class of B vitamins. As this is a water-soluble vitamin, excess of it gets excreted in the urine and is not retained by the body. Hence, daily intake of this vitamin becomes essential for optimal functioning of the body.

Functions of Vitamin B7

ChocolateBiotin helps in the synthesis of energy/glucose by breaking down fats, carbohydrates and proteins. It thereby facilitates the uptake of glucose by several cells of the body for their functions. In this regard, research has shown that regular intake in diabetic individuals may be beneficial in controlling blood glucose levels. Biotin also provides health and strength to nails, skin and hair. Vitamin B7 is also essential for maintaining appropriate functioning of the nervous system.

Food Sources of Vitamin B7

The food sources of Vitamin B7 are as follows:

  • chocolates
  • milk
  • nuts and oilseeds
  • soya bean
  • yeast
  • cereals
  • pork
  • organ meats and egg yolk

Do note that egg yolk is a rich source of biotin, but raw uncooked egg white contains compounds that act as inhibitors for biotin. Rich sources of biotin are:

  • chicken liver (a 100g serving contains as much as 170mcg of biotin)
  • yeast (which contains about 200mcg of biotin).
  • egg yolk (about 100gm of egg yolk contains 60mcg of vitamin B7)

Moderate sources of Vitamin B7 include:

  • fish (a 100gm serving of fish contains about 3-24mcg of biotin, depending on the quality and the variety of fish)
  • oatmeal (contains about 22-31mcg of biotin)
  • various nuts such as walnuts and peanuts (a 100gm serving contains about 39mcg and 34mcg of biotin, respectively)

Factors of Vitamin B7 Deficiency

Raw egg whites contain a compound known as avidin which inhibits the absorption of biotin in the body. Individuals consuming raw uncooked eggs for months together may actually experience serious health consequences. The condition stated above is just one example that can actually lead to Vitamin B7 deficiency. Other conditions where a deficiency of biotin can set in include:

  • intravenous nutrition and Total Parenteral Nutrition (TPN) given to seriously ill patients
  • smoking cigarettes: a causative factor as nicotine inhibits the absorption of vitamin B7

Symptoms of Vitamin B7 Deficiency

Deficiency symptoms include:

  • dry scaly skin
  • dermatitis
  • anorexia
  • vomiting
  • nausea
  • alopecia
  • depression
  • hallucinations
  • tingling sensation in the arms and legs
  • listlessness

Dosage of Vitamin B7 Supplements

So far, there is no Recommended Dietary Allowance (RDA) established for Vitamin B7. We only have daily adequate intake (AI) available given by NIN and Food Nutrition Board. The recommended intake or adequate requirements of Vitamin B7 is given below:


  • 0 – 12 months: 7mcg / day (reads as 7 microgram per day)


  • 1 – 3 years: 8mcg / day
  • 4 – 8 years: 12mcg / day
  • 9 – 13 years: 20mcg / day
  • 14 – 18 years: 25mcg / day


  • 18 years and above: 30mcg / day
  • Pregnant women: 30mcg / day
  • Lactating women: 35mcg / day