Not all pregnancy vitamins are worth the money, experts say. But one of them is proven to prevent devastating birth defects — and fewer women than ever are taking it.

New NHS data shows fewer than one in five women in England are now taking folic acid before pregnancy. Experts warn the sharp decline could put babies at needless risk.

Skipping folic acid before conception is linked to neural tube defects, including spina bifida, a serious condition affecting the brain and spine.

A new paper, published in BJOG: An International Journal of Obstetrics and Gynaecology, shows uptake has collapsed in just a few years. Some 26 per cent of women took it before pregnancy in 2020/21, a figure that has now dropped below 20 per cent in 2024/25.

Why Timing Matters Most

Taking folic acid before conception and during the first 12 weeks can reduce the risk of these defects. But the protective window closes fast.

The neural tube usually finishes forming by the end of the fourth week after conception. Many women do not yet know they are pregnant at that point.

'It is therefore worrying to see the number of women taking supplements before pregnancy continuing to fall,' said Dr Danielle Schoenaker. She is an NIHR Advanced Fellow at the University of Southampton and led the commentary.

'Taking folic acid before pregnancy is one of the simplest and most effective steps women can take to support a healthy start for their baby,' she said. Many people do not realise how early foetal development begins, she added.

'Waiting until after a positive pregnancy test can be too late to gain the full protective benefits of folic acid,' she said. That timing gap is at the heart of the concern.

One Vitamin, Not Twenty

Confusion may be part of the problem. A review in Drug and Therapeutics Bulletin found many pregnancy multivitamins, some containing over 20 ingredients, are heavily marketed but largely unproven.

That review found no solid evidence that expensive multi-nutrient blends improve outcomes for mother or baby. It concluded most women do not need them at all.

But it confirmed one clear exception: folic acid, alongside vitamin D, remains backed by real evidence. Both are cheap and available from any pharmacy.

The irony, researchers suggest, is that the one supplement genuinely worth taking is the one women are increasingly skipping, while unproven blends continue to be marketed heavily.

A Fix That Falls Short

The Government will introduce mandatory folic acid fortification of non-wholemeal wheat flour from December 2026. Researchers have broadly welcomed the move.

But they caution it is not a complete solution. Fortified flour alone will not deliver enough folic acid for everyone, official guidance states.

Professor Keith Godfrey, from the University of Southampton, co-authored the paper. He said a wider strategy is needed.

'We need a joined-up approach,' he said, combining stronger fortification with better education and accessible preconception care.

The data also reveals stark inequalities in who is missing out. Uptake is lower among women in deprived areas and some ethnic minority groups, though London has bucked the trend.

Separate Southampton research found broader nutritional gaps among expectant mothers, with 90 per cent of over 1,700 women studied lacking key vitamins overall.

Researchers are now calling for public health campaigns that explain folic acid's proven benefits clearly, while tackling misinformation about which pregnancy vitamins actually work.

Frequently Asked Questions

  • Why is folic acid important before pregnancy?
    Folic acid is crucial before pregnancy as it helps prevent neural tube defects in the developing foetus.
  • When should women start taking folic acid?
    Women should start taking folic acid at least one month before conception and continue through the first 12 weeks of pregnancy.
  • Are multivitamins necessary during pregnancy?
    Most multivitamins are not necessary during pregnancy, but folic acid and vitamin D are recommended.
  • What is the government's plan regarding folic acid fortification?
    The government plans to introduce mandatory folic acid fortification of non-wholemeal wheat flour from December 2026.
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