First Trimester Vitamins: Complete Guide
Supplement aisles can feel overwhelming once you're pregnant, with dozens of pregnancy-branded products all claiming to be essential. In reality, the first trimester only calls for two supplements that really matter, plus a few things worth avoiding — everything else is optional on top.
The two essentials
- Folic acid (400mcg daily) — the single most important early-pregnancy supplement. It's taken from before conception if possible and continued until the end of week 12, as it significantly reduces the risk of neural tube defects such as spina bifida. If you didn't start it before finding out you were pregnant, begin as soon as you know — it still helps.
- Vitamin D (10mcg daily) — recommended for all adults in the UK, and particularly important during pregnancy for bone health, both yours and your baby's. Unlike folic acid, this one is recommended for the whole pregnancy, not just the first trimester.
Making it simple with a multivitamin
Rather than buying folic acid and vitamin D separately, most people find it easier to take a pregnancy-specific multivitamin that combines both at the correct doses, along with other nutrients like iodine. Well-known UK brands include Pregnacare, Centrum Pregnancy, and Sanatogen Pregnancy — there's no strong evidence that any particular branded product outperforms the others, so it largely comes down to preference, budget, and which one agrees with your stomach (some people find certain formulations easier to tolerate if nausea is an issue).
If you're eligible for free vitamins
If you're under 18, or on certain benefits, you may be eligible for free Healthy Start vitamins through the NHS Healthy Start scheme, which include folic acid and vitamin D. It's worth checking your eligibility, as this can make a real difference to the cost of the first trimester.
What to avoid
- High-dose vitamin A (retinol) — excess vitamin A in this form has been linked to birth defects, so pregnancy multivitamins are formulated without it or use a safe alternative form (beta-carotene) instead.
- Cod liver oil — typically high in vitamin A, so it's generally avoided during pregnancy for the same reason.
- Random extra supplements — unless your GP or midwife has specifically recommended something (such as iron following a blood test), there's usually no need to add further individual supplements on top of a standard pregnancy multivitamin.
Iron and omega-3
Iron isn't routinely recommended unless a blood test shows you're deficient — taking extra iron you don't need can cause uncomfortable side effects like constipation. If you don't eat oily fish, you might consider a vegetarian or algae-based DHA supplement, since omega-3 fatty acids support the baby's brain and eye development, though this is a personal choice rather than a strict requirement.
Frequently Asked Questions
What vitamins do I need in the first trimester?
The two essentials are folic acid (400mcg daily, continued until week 12) and vitamin D (10mcg daily, continued throughout pregnancy). A pregnancy multivitamin usually covers both alongside other nutrients like iodine, so many people find it simpler than taking separate supplements.
Why is folic acid important in the first trimester?
Folic acid significantly reduces the risk of neural tube defects, such as spina bifida, which develop very early in pregnancy — often before many people even know they're pregnant. That's why it's recommended from before conception where possible, but starting as soon as you find out is still worthwhile.
Can I take my normal multivitamin instead of a pregnancy one?
It's best to switch to a pregnancy-specific multivitamin rather than continuing a general one, because standard multivitamins can contain higher levels of vitamin A than are considered safe in pregnancy. Pregnancy multivitamins are formulated specifically to include folic acid and vitamin D at the right doses while avoiding retinol-based vitamin A.
This article is for informational purposes only and does not constitute medical advice.
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