Vitamins and supplements in pregnancy

Check the ingredients label before you buy a pregnancy supplement. NHS advice is to avoid cod liver oil and supplements that contain vitamin A (also called retinol), because too much can harm a baby’s development. Ask your pharmacist about any supplements you were taking before pregnancy too.

When to take folic acid

Folic acid lowers the chance of neural tube defects, which are problems with the baby’s developing brain or spine. The NHS says it’s hard to get enough from food alone. A varied diet still matters, but it doesn’t replace the recommended folic acid supplement.

In the UK, the NHS recommends 400 micrograms of folic acid every day. It’s best to start 3 months before pregnancy, or as soon as you find out. The NHS recommends taking it for the first 12 weeks. If the pregnancy was unexpected, you should still start when you find out.

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

This advice changed recently. The current NHS guidance on folic acid includes sickle cell anaemia and thalassaemia among the conditions where you should talk about a higher prescribed dose. Diabetes, a past pregnancy affected by a neural tube defect, and some medicines are also reasons to get advice for you. Ask your GP rather than choosing a dose 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 isn’t enough sunlight at this time of year for the body to make enough vitamin D. Vitamin D helps a baby’s bones and teeth develop.

Some people need vitamin D all year round. NHS advice includes people who cover most of their skin when outside, or who spend a lot of time indoors. It says people with black or brown skin can think about taking it all year round. Ask your midwife or GP if you’re not sure how this applies to you.

US NIH guidance gives a recommended daily amount of vitamin D of 15 mcg (600 IU) for pregnant and breastfeeding teenagers and women. That’s your total intake for the day. It doesn’t mean adding that amount on top of a pregnancy vitamin. Talk to your clinician or pharmacist about the products you already take.

Iron advice differs between countries

The NHS says your iron levels are checked in routine pregnancy blood tests, and your GP or midwife can recommend iron supplements. Your body needs iron to make red blood cells, which carry oxygen. Tell your care team if tiredness is bothering you, rather than assuming you need to buy extra iron.

WHO recommends taking iron and folic acid every day during pregnancy. In contrast, USPSTF says there isn’t enough evidence to judge the benefits and harms of routine iron supplements for pregnant people without symptoms. This doesn’t mean you shouldn’t treat low iron. The review leaves out people with symptoms or with conditions that mean they need more iron.

Iodine and what a prenatal product contains

Iodine helps the body make thyroid hormones, which support bone and brain development during pregnancy and babyhood. NIH names seafood, eggs and dairy foods as good sources. It notes that people who eat few or none of these foods may not get enough. Mention a vegan diet, or any foods you don’t eat, when you go through your supplements.

NIH reports that some professional bodies recommend iodine supplements during pregnancy, but only about half of US pregnancy multivitamins contain iodine. Ask your doctor or pharmacist to check the label and what you need. Get advice before you combine 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 check the exact products you use. Bring the packets or a clear photo of the ingredients. Put any prescribed supplements on the list too, and ask what each product is meant to do.

People on NHS Healthy Start can get 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 pick them up. Northern Ireland has a separate way to ask for them and sends them by post. Ask about the arrangements where you live.