Vitamins and supplements in pregnancy

Check the ingredient label before buying a pregnancy supplement. NHS advice is to avoid cod liver oil and supplements containing vitamin A, also called retinol, because too much can harm a baby’s development. Ask your pharmacist about supplements you were using before pregnancy too.

When to take folic acid

Folic acid reduces the chance of neural tube defects, problems affecting the developing brain or spine. The NHS says it is difficult to get the amount needed from food alone. A varied diet still matters, but it does not replace the recommended folic acid supplement.

In the UK, the NHS recommends 400 micrograms of folic acid every day, ideally from 3 months before pregnancy or as soon as you find out. It recommends taking folic acid for the first 12 weeks. If pregnancy was unexpected, the guidance still includes starting when you discover it.

In the US, USPSTF recommends 0.4 to 0.8 mg (400 to 800 mcg) daily for people planning or able to become pregnant. It recommends starting at least 1 month before conception and continuing through the first 2 to 3 months of pregnancy. These public-health recommendations differ by country, so use the guidance for where you live.

Advice has changed recently. The current NHS folic acid guidance includes sickle cell anaemia and thalassaemia among conditions needing a discussion about a higher prescribed amount. Diabetes, a previous pregnancy affected by a neural tube defect, and certain medicines are also reasons for individual advice. Ask your GP rather than selecting an amount yourself.

Vitamin D supplements and daily intake

UK guidance recommends 10 micrograms of vitamin D every day between early October and late March. The NHS explains that there is not enough sunlight for the body to make enough vitamin D during this time. Vitamin D helps a baby’s bones and teeth develop.

Some people need vitamin D throughout the year. NHS advice includes people who cover most of their skin outside or spend much of their time indoors, and says people with black or brown skin can consider year-round supplementation. Ask your midwife or GP if you are unsure how this applies to you.

US NIH guidance lists a daily recommended vitamin D amount of 15 mcg (600 IU) for pregnant and breastfeeding teens and women. That amount refers to total daily intake. It does not mean adding that amount on top of a prenatal product. Discuss the products you already use with your clinician or pharmacist.

Iron advice differs between countries

The NHS says iron levels are checked during routine pregnancy blood tests, and your GP or midwife can recommend iron supplements. Iron is needed to make red blood cells, which carry oxygen. Tell your care team about troublesome tiredness rather than assuming you need to buy extra iron.

WHO recommends daily iron and folic acid during pregnancy. In contrast, USPSTF says evidence is insufficient to assess the benefits and harms of routine iron supplementation in pregnant people without symptoms. This does not advise against treating iron deficiency. The review excludes people with symptoms or specific conditions that increase iron needs.

Iodine and what a prenatal product contains

Iodine helps the body make thyroid hormones, which support bone and brain development during pregnancy and infancy. NIH identifies seafood, eggs and dairy foods as useful sources, and notes that people eating few or none of these foods may not get enough. Mention a vegan diet or other food exclusions when reviewing supplements.

NIH reports that some professional organisations recommend iodine supplements during pregnancy, while only about half of US prenatal multivitamins contain iodine. Ask your doctor or pharmacist to check the label and your needs. Get advice before combining several products.

Get help checking products and covering costs

Ask your midwife, GP or pharmacist in the UK, or your doctor, midwife or pharmacist elsewhere, to review the exact products you use. Bring their packaging or a clear photograph of the ingredients. Put any prescribed supplements on the list too, and ask what each product is intended to provide.

People on NHS Healthy Start are entitled to free vitamins. Its pregnancy tablets contain folic acid, vitamin C and vitamin D. In England and Wales, ask your midwife or health visitor where to collect them. Northern Ireland uses a separate request and postal process; ask about the arrangements where you live.