Biotin (Vitamin B7): ICMR-NIN Intake, Indian Sources, Hair Claims and Blood Test Interference

Biotin is vitamin B7, a water-soluble vitamin that a handful of enzymes need in order to process fat, carbohydrate and protein. ICMR-NIN's Nutrient Requirements for Indians 2020 proposes an adequate intake of 40 mcg a day for adults, a quantity measured in millionths of a gram. Deficiency from an ordinary diet is rare. The reason most people meet the word is the hair and nail market, where a single tablet often carries 10 mg, which is 250 times the adult figure. This entry in the vitamins section of the handbook sets the requirement beside the evidence for those tablets.

What does biotin do in the body?

It serves as a co-enzyme, a small helper that certain enzymes cannot work without. The joint FAO and WHO expert consultation on vitamin requirements explains that in humans biotin operates within four carboxylases, enzymes that attach a unit of bicarbonate to another molecule. Through them biotin takes part in making fatty acids, in producing glucose and in breaking down the amino acid leucine.

Skin and hair enter the story through deficiency, not through any special action on hair. When biotin runs out, the consultation lists a red, scaly dermatitis, conjunctivitis and loss of hair among the signs. From that list the supplement trade has reasoned backwards, that extra biotin must make more hair. The trials described further down do not bear this out.

How much biotin do Indians need under ICMR-NIN's 2020 values?

ICMR-NIN's 2020 report proposes 40 mcg a day for adults and pregnant women, with an additional 5 mcg a day for lactating women to make up for losses through breast milk. For children it proposes 20 mcg at 1 to 3 years and 25 mcg at 4 to 10 years, and for adolescents 35 mcg. All of these are adequate intakes, not recommended dietary allowances: the main tables of the report omit biotin and send the reader to the text. The table of tolerable upper limits has no biotin column.

The Indian figures sit about a third above the international ones, and neither set is built on a measured requirement. The FAO and WHO consultation started from the biotin in breast milk, roughly 6 mcg a litre, worked out an infant's intake of 5 mcg a day and scaled it up by body weight for children and adults. Treat 40 mcg as a sensible target, not a threshold below which harm begins.

Which Indian foods supply biotin in a normal portion?

Egg, paneer, khoa, mushrooms and a few nuts and seeds stand out in the Indian Food Composition Tables 2017. Egg yolk is the richest common food at 65.22 mcg per 100 g raw, which works out at 18.24 mcg per 100 g for the whole egg. Milk is modest at about 2 mcg per 100 g, yet the nutrient panel for paneer shows 21.04 mcg. The portions below are calculated from those tables. The site has no ranked biotin table; the full panels are in the nutrient tables for Indian foods.

Two things in this table surprise people. Pulses and groundnuts, often named as biotin foods, are low in the Indian analyses: whole moong has 1.35 mcg per 100 g and groundnut 1.61 mcg. And the staples, rice and atta, add almost nothing. A normal vegetarian day added up from these figures lands below 40 mcg, as the worked example shows. The consultation itself says the food content and bioavailability of biotin need further investigation, so food table totals for this vitamin should be read loosely.

Raw egg white and the other real causes of deficiency

The classic cause is eating raw egg white for a long time. The consultation states that biotin deficiency in humans has been clearly documented with prolonged consumption of raw egg whites, which contain avidin, a protein that binds biotin. A 2017 review of biotin and hair adds that avidin is denatured by cooking, so a boiled egg or an omelette poses no such problem. The page on egg white against whole egg compares the two parts.

A case from 1981 shows what happens. An 11-year-old boy whose prescribed diet contained raw eggs lost all his hair and developed a red, peeling rash, with laboratory signs that his biotin-dependent enzymes had stopped working. Treatment by his doctors and the removal of raw eggs reversed every abnormality.

Is biotin deficiency common in India?

Nobody knows from blood tests. The consultation judges that dietary deficiency in otherwise normal people is probably rare. No national figure for biotin status in Indians was found while preparing this entry. One intake study exists: among 340 lactating women from Scheduled Tribe communities in Guntur district, Andhra Pradesh, a 24-hour recall analysed with the Indian food tables gave a mean biotin intake of 11.09 mcg a day, and every mother was below the ICMR level. The study did not examine the women for signs of deficiency.

Pregnancy is the one stage where researchers suspect a quiet shortfall. An American group reported that about half of pregnant women pass more of a marker called 3-hydroxyisovaleric acid in urine, and in a randomised trial of 26 such women, 14 days of biotin brought the marker down while placebo did not. That shows biotin status dips in pregnancy, not that mothers or babies are harmed, and neither ICMR-NIN nor the consultation raises the figure for pregnancy. Food for those months is in the pregnancy diet guide.

Do biotin supplements help hair and nails?

In people who are not deficient, no trial has shown that they do. A 2017 review searched the medical literature and found 18 reported cases of biotin used for hair and nail changes. Every patient had an underlying condition, such as an inherited enzyme deficiency or brittle nail syndrome, and all improved. The reviewers concluded that such cases are uncommon, that no randomised controlled trial had tested biotin in normal, healthy individuals, and that evidence for supplementing healthy people is lacking.

A 2024 review that excluded case reports found only three studies. The best of them, a double-blind trial from 1966 in women with diffuse hair loss, gave biotin to 28 and placebo to 18: after four weeks both groups had improved and there was no significant difference. The other two, in patients on isotretinoin and in women after weight-loss surgery, were open to bias and showed nothing striking.

How does biotin interfere with thyroid and troponin tests?

Many laboratory tests use biotin as part of their own chemistry, and biotin from a tablet gets in the way. In a study published in JAMA in 2017, six healthy adults took 10 mg of biotin a day for seven days and had 11 substances measured by 37 different assays. Results were distorted in 9 of the 23 assays built on biotin, 39 per cent, and in none of the 14 that were not. Of the affected designs, 5 of 8 competitive assays read falsely high and 4 of 15 sandwich assays read falsely low.

For the thyroid this can paint a convincing false picture: thyroid hormones reading high and TSH reading low, the pattern of an overactive gland. A case report written by doctors in Thiruvananthapuram and the United States describes a 64-year-old man taking 10,000 mcg of biotin a day whose results looked like hyperthyroidism. He was given anti-thyroid medicine for two months before the supplement came to light; five days after the biotin was stopped his results were normal.

The heart test at stake is troponin, used in emergency rooms to detect a heart attack. A 2019 laboratory study found that 10 mg of biotin a day caused significant interference in one troponin T assay, while two other troponin assays were unaffected, and warned that the result could be a delayed or missed diagnosis of heart muscle injury.

Regulators' warnings on biotin and laboratory tests

The United Kingdom's MHRA told health professionals in its May 2025 safety roundup that biotin may interfere with thyroid immunoassays, that the risk rises with dose, and that people with suspected thyroid dysfunction should be asked about their biotin intake. The 2024 hair review records that the United States FDA issued a safety communication in 2017 and a reminder in 2019 focused on troponin, and that a death has been reported after biotin interference led to a missed heart attack. No equivalent Indian notice was found for this entry.

A worked example: a hair gummy before a thyroid test

This is an illustration, not a real person. Take a 29-year-old vegetarian marketing executive in Chennai with an adequate intake of 40 mcg. Her food for a day: two chapatis (0.46 mcg), 75 g of raw rice (0.45 mcg), masoor dal (30 g, 0.38 mcg), a glass of milk (3.96 mcg), 50 g of paneer (10.52 mcg), 100 g of spinach (4.14 mcg), 30 g of walnuts (3.92 mcg), 100 g of papaya (3.05 mcg) and 100 g of potato (1.35 mcg). By the Indian tables that comes to about 28 mcg; the paneer and spinach could be a palak paneer.

Now add the hair product a colleague recommended, labelled 10,000 mcg. That one tablet is 250 times her adequate intake and roughly 350 times what her food supplied. She has no risk factor for deficiency, so the trials give no reason to expect a benefit. She is also due a thyroid test next week because of tiredness. The decision is not hers to make from a web page: she should tell the doctor and the laboratory about the tablet before the sample is taken, and let them decide on timing.

Common mistakes and myths about biotin

The second mistake is to treat a vitamin as too harmless to mention to a doctor. The third is to drink raw eggs for protein, which blocks the very vitamin being bought in a bottle. The fourth is to judge a product by the size of its number, as if 10,000 mcg must work better than 40. What matters for hair is finding the cause, the subject of the article on diet for hair fall.

Too much biotin, safety and when to see a doctor

Biotin itself has not been shown to poison anyone. The FAO and WHO consultation says toxicity is not a problem because absorption from the gut is limited, and ICMR-NIN sets no upper limit. The danger is indirect: a wrong test result, followed by a wrong diagnosis or a missed one. Pregnant and breastfeeding women, people with thyroid or heart conditions, anyone on medicines for epilepsy and anyone due for blood tests should not start a high-dose biotin product without asking their doctor.

FSSAI's rules for a biotin supplement

India's food regulator lists one permitted form, D-biotin, in its regulations on health supplements and nutraceuticals. The compendium of those regulations states that the quantity of a nutrient added shall not exceed the recommended daily allowance specified by ICMR. A pack must carry the words "HEALTH SUPPLEMENT", declare the amount of each nutrient and show it as a percentage of the ICMR allowance, and print "NOT FOR MEDICINAL USE". Its labelling may not claim that it prevents, treats or cures a human disease. Against 40 mcg, a tablet of 10,000 mcg is 25,000 per cent.

Learning this properly

Biotin is taught at NNWA, a private skill academy in Kolkata whose classes are held online in English and Hindi. The courses train people to coach healthy clients and to pass medical cases to a doctor; none of them is a degree or a dietitian qualification. The Diploma in Nutrition, Dietetics and Public Health covers the vitamins, and the Clinical Nutrition course covers diet in illness.