Pregnancy Vitamins: What You Need and When

The supplement aisle can feel overwhelming when you're pregnant. Dozens of prenatal vitamins, each claiming to be essential. Here's what the evidence says you genuinely need, what's nice to have, and what's marketing.

The essential: Folic acid

Folic acid is the single most important supplement in early pregnancy. It significantly reduces the risk of neural tube defects (conditions affecting the brain and spine, such as spina bifida).

How much: 400 micrograms daily. If you have a higher risk (previous neural tube defect pregnancy, diabetes, BMI over 30, or taking certain medications), your GP may prescribe 5mg daily.

When to take it: Ideally from before conception through to at least week 12. The neural tube forms in the first 28 days after conception - often before you know you're pregnant. If you didn't take it before pregnancy, start as soon as you find out. It still helps.

Where to get it: Available over the counter at any pharmacy for around GBP 2-5 for a three-month supply. Also included in all prenatal multivitamins.

The recommended: Vitamin D

The NHS recommends all pregnant and breastfeeding women take 10 micrograms (400 IU) of vitamin D daily. In the UK, we don't get enough sunlight for adequate vitamin D production, especially between October and March.

Vitamin D supports baby's bone development and your own bone health. If you're eligible for Healthy Start vouchers, you can get free vitamin supplements from your midwife or local pharmacy.

The "probably helpful": Iron

Your blood volume increases by up to 50% during pregnancy. Many women become iron-deficient, causing fatigue, breathlessness, and pale skin. Your midwife will check your haemoglobin levels at your booking appointment and again at 28 weeks. If you're low, they'll prescribe iron tablets. If your levels are normal, focus on iron-rich foods: red meat, leafy greens, lentils, fortified cereals, and dried fruit.

Taking iron with vitamin C improves absorption. Avoid taking it with tea or coffee, which inhibit absorption.

The "probably fine but not essential": Omega-3

DHA (an omega-3 fatty acid) supports baby's brain and eye development. If you eat oily fish regularly (salmon, sardines, mackerel - but not more than two portions per week due to mercury), you're probably getting enough. If not, a supplement is reasonable.

What about prenatal multivitamins?

A good prenatal multivitamin containing folic acid, vitamin D, and iron covers your bases. If you choose one, check it includes folic acid (400 micrograms) and vitamin D (10 micrograms). Popular UK options include Pregnacare, Seven Seas, and supermarket own-brand versions. The expensive ones aren't necessarily better.

What to avoid

Vitamin A (retinol). High doses can harm your baby. Avoid liver and liver products during pregnancy, and check that any multivitamin doesn't contain retinol (beta-carotene, the plant form, is safe).

Excessive doses of anything. More isn't better. Stick to recommended amounts.

Herbal supplements. Many herbal remedies haven't been tested for safety in pregnancy. Avoid them unless specifically recommended by your healthcare provider.

The bottom line

The evidence-based minimum is simple: folic acid (400 micrograms) from preconception to week 12, and vitamin D (10 micrograms) throughout pregnancy and breastfeeding. Everything else is secondary. Eat a varied, balanced diet where you can, and don't stress about perfection.