Folate and Folic Acid (Vitamin B9): ICMR-NIN Values, Indian Sources, Neural Tube Defects and the IFA Tablet

Folate is vitamin B9, a water-soluble vitamin that cells need to copy DNA and to make red blood cells. Folic acid is the synthetic form found in tablets and fortified foods. ICMR-NIN's Nutrient Requirements for Indians 2020 sets the allowance at 300 mcg a day for an adult man, 220 mcg for an adult woman and 570 mcg in pregnancy. This entry in the vitamins section of the handbook gives the values for every age, the Indian foods that carry folate, the survey figures, and what the national programme advises before and during pregnancy.

What is the difference between folate and folic acid?

Folate is the family of forms that occurs naturally in food; folic acid is one manufactured form. The joint FAO and WHO expert consultation on vitamin requirements describes two practical differences. Natural folates lose activity in food over days or weeks, while folic acid stays stable for months or even years. And food folate is only about 50 per cent available to the body, whereas folic acid taken with food is about 85 per cent available.

This is why requirements are written as dietary folate. ICMR-NIN's 2020 report uses the same conversion as the consultation: 1 mcg of food folate equals 0.5 mcg of folic acid taken on an empty stomach, or 0.6 mcg taken with a meal. A 400 mcg folic acid tablet swallowed on an empty stomach is therefore worth about 800 mcg of food folate. Folic acid on a label and folate in a food table cannot simply be added.

What does folate do in the body?

It carries the single-carbon units that cells use to build DNA, so every dividing cell depends on it. The FAO and WHO consultation explains that when folate runs short, cell division slows and the effect shows first where cells divide fastest: red cell production falls, producing anaemia, and white cells, platelets and the lining of the gut are affected too. ICMR-NIN's 2024 Dietary Guidelines describe it as a B vitamin essential for the multiplication and maturation of red cells.

A second pathway recycles the amino acid homocysteine, and it needs vitamin B12 as well as folate. With too little folate, homocysteine in the blood rises; the consultation calls it a very sensitive indicator of folate status. This is why folate and vitamin B12 are looked at together.

How much folate do you need under ICMR-NIN's 2020 values?

An adult man needs 300 mcg a day and an adult woman 220 mcg, counted as dietary folate. The expert group revised the figures using Indian data on intake, plasma folate and homocysteine, and took the intake that keeps plasma folate above 10 nmol per litre as the average requirement: 250 mcg for men and 180 mcg for women. Pregnancy adds 300 mcg to that and lactation 100 mcg, which gives allowances of 570 mcg and 330 mcg.

Pregnancy is the row to notice: 570 mcg is more than two and a half times a woman's usual 220 mcg. The upper limits describe habitual intake judged unlikely to cause harm. For women aged 60 and over the report's annexure lists 200 mcg, a little below the 220 mcg for younger women.

Which Indian foods carry the most folate per portion?

Pulses and green leafy vegetables are the everyday sources, and liver is the richest single food. The table converts the per 100 g values of the Indian Food Composition Tables 2017 into household portions, using raw weights throughout. The ranked list of every food is in the folate table of Indian foods, and the rajma page has one full panel.

Two cautions apply to every row. The figures are for raw food, and the consultation warns that half or even three-quarters of a food's folate activity can be lost between harvest, storage, processing and cooking. ICMR-NIN's guidelines advise boiling pulses in just enough water, with none drained off, as the best way to keep their folate. The staples carry little; palak paneer or a sprouts salad adds a folate-dense item.

Folate deficiency in India: the survey figures

The Comprehensive National Nutrition Survey of 2019, as tabulated in ICMR-NIN's 2024 guidelines, found folate deficiency in 23.4 per cent of children aged 1 to 4, 28.2 per cent at 5 to 9 and 36.7 per cent of adolescents aged 10 to 19. In that oldest group it was more common than iron deficiency, at 21.5 per cent, or vitamin B12 deficiency, at 30.9 per cent.

The blood picture is an anaemia with larger red cells than normal: the consultation lists a raised mean corpuscular volume among the early indicators. The groups the consultation names as at risk are people on a limited diet, those with malabsorption such as coeliac disease and tropical sprue, pregnant women, whose requirement rises sharply, and breastfeeding women, who lose folate in milk.

Why does folic acid matter before conception?

Because the structure it protects forms in the first month. The FAO and WHO consultation explains that the neural plate closes between days 21 and 27 after conception to form what becomes the spinal cord and skull; when closure fails the result is a neural tube defect such as spina bifida or anencephaly. It reports a ten-fold difference in risk between poor and adequate folate status, and it states that a diet based on food folate alone will not be optimal for prevention, given its lower availability and stability.

India's advice follows from this. The Ministry of Health and Family Welfare's operational guidelines for the national anaemia programme advise all women of reproductive age to take 400 mcg of folic acid daily in the pre-conception period and up to the first trimester, to reduce neural tube defects. ICMR-NIN's 2024 guidelines call folic acid in the first 28 days of pregnancy essential and advise a 500 mcg supplement through the first 12 weeks. The pregnancy diet guide sets this in the context of the whole diet.

How common these defects are in India is known only roughly. A 2015 systematic review of Indian studies put the pooled birth prevalence at 4.5 per 1,000 total births, high compared with other regions, but most of the studies were hospital based and of low to moderate quality.

Folic acid in India's national programme and in fortified staples

Folic acid reaches most Indians as the second ingredient of the iron and folic acid (IFA) tablet or syrup. The table lists the folic acid content the programme's 2018 guidelines specify for prevention in each group. It is given here as a record of what the programme supplies, not as a suggestion to dose yourself; the iron in the same tablets is covered in the iron entry.

In NFHS-5, 87.6 per cent of women who had given birth in the previous five years had received or bought IFA during that pregnancy, yet 44.1 per cent took it for at least 100 days and 26.0 per cent for 180 days or more. Fortified staples add only a little: FSSAI's standards set folic acid in fortified atta and fortified rice at 75 to 125 mcg per kilogram, so 300 g of fortified rice in a day supplies about 23 to 38 mcg. That does not stand in for the pre-conception tablet.

What does the evidence say about folic acid?

For preventing neural tube defects the evidence is about as strong as nutrition evidence gets. The Medical Research Council Vitamin Study, published in 1991, randomised 1,817 women who had already had an affected pregnancy, at 33 centres in seven countries. Among 1,195 completed pregnancies there were 6 neural tube defects in the folic acid groups and 21 in the others, a 72 per cent protective effect. The Cochrane review of 2015, with five trials and 7,391 women, found a risk ratio of 0.31 for daily folic acid and rated that evidence high quality.

The same review found no clear effect, in either direction, on cleft lip, cleft palate, congenital heart defects or miscarriage. Beyond pregnancy the picture is narrower. A trial in China of 20,702 adults with high blood pressure recorded fewer first strokes over a median of 4.5 years when folic acid was added to their blood pressure medicine, 2.7 against 3.4 per cent. Its authors relate the benefit to low folate levels at the start, so it is no reason for well-nourished people to take tablets.

A worked example: a vegetarian day and the pre-conception question

This is an illustration, not a real person. Take a 27-year-old vegetarian bank officer in Kolkata who plans to conceive next year. Her day holds chana dal (30 g raw, 55 mcg), a spinach sabzi (100 g raw, 142 mcg), two chapatis (60 g atta, 18 mcg), rice (60 g raw, 6 mcg), rajma at dinner (30 g raw, 95 mcg), a glass of milk (14 mcg) and a handful of groundnuts (30 g, 27 mcg). On raw weights the total is 357 mcg, comfortably above her allowance of 220 mcg.

Two adjustments change the reading. If half the folate is lost in storage and cooking, which is the lower of the consultation's two estimates, about 180 mcg reaches her, level with the average requirement and no more. And the pregnancy allowance is 570 mcg, which even her raw total misses by 213 mcg. The 400 mcg folic acid tablet the programme advises before conception counts for about 800 mcg of food folate on an empty stomach. The example shows why the advice is food and the tablet together, begun before conception, under the doctor she will see for the pregnancy.

Common mistakes and myths about folate

The second mistake is to treat folate and folic acid figures as one unit, when 1 mcg of folic acid on an empty stomach counts as 2 mcg of food folate. The third is to boil pulses in a lot of water and pour it away. The fourth is to take folic acid for tiredness or a low haemoglobin without a test, which can hide a vitamin B12 deficiency. The fifth is to stop IFA when the first strip runs out, though the programme's schedule in pregnancy is a minimum of 180 days.

Too much folic acid, vitamin B12 and when to see a doctor

ICMR-NIN's tolerable upper limit is 1,000 mcg a day for adults, pregnant and lactating women included. The FAO and WHO consultation finds no evidence that natural folate from food can be eaten in amounts that pose a risk; the limit concerns folic acid in supplements and fortified foods. Its main worry is masking: high intakes of folic acid correct the anaemia of vitamin B12 deficiency while the nerve damage progresses undiagnosed, to a point where it may be irreversible even after B12 is given.

That matters in India, where the 2019 national survey found vitamin B12 deficiency in 30.9 per cent of adolescents. A 2016 review reported that in older adults with low B12, high blood folate went with worse anaemia and cognitive impairment. These are observational findings, weaker than the trial evidence for benefit in early pregnancy. They argue for the advised amount and for checking B12, not for avoiding folic acid.

Learning this properly

Folate is taught at NNWA within the B vitamins, anaemia and nutrition in pregnancy. The academy is a private skill institution based in Kolkata, teaching online in Hindi and English. Its courses prepare learners to coach healthy people and pass medical cases to a doctor; none of them is a degree or a dietitian qualification. The Public Health Nutrition course looks at supplementation and fortification programmes, and the Clinical Nutrition course at nutrition alongside medical care.