> ## Content Index > Fetch the complete content index at: https://verinourishwomen.com/llms.txt > Use this file to discover other available public pages before exploring further. # Prenatal vitamins: what you actually need and when to start - URL: https://verinourishwomen.com/pregnancy/prenatal-vitamins/ - Published: 2026-07-08T00:00:00.000Z - Updated: 2026-09-08T09:58:43.000Z - Description: Which pregnancy supplements matter, how much folic acid and vitamin D to take, what to avoid, and when to start. A practical, evidence-based guide. - Author: VeriNourish Editorial Team - Tags: Pregnancy *Written and evidence-checked by the [VeriNourish Editorial Team](https://verinourishwomen.com/editorial-team/) against 4 named sources listed below. No licensed clinician reviews this content.* Pregnancy supplements are surrounded by marketing, but the evidence points to a short, clear list. You do not need a cupboard full of pills. Folic acid and vitamin D are standard UK advice, while iron guidance differs by country and individual blood results. Here is what actually matters and when to start. ## The UK essentials For most women receiving care in the UK, folic acid and vitamin D are the routine starting points. | Supplement | How much | When | | ---------- | ---------------------------- | ------------------------------------------------ | | Folic acid | 400 micrograms a day | From before conception to the end of week 12 | | Vitamin D | 10 micrograms (400 IU) a day | Autumn and winter, or year-round with little sun | These are the UK figures: the NHS advises 400 micrograms of folic acid daily for the first 12 weeks, and 10 micrograms of vitamin D daily from early October to late March, or year-round if you get little sun or have darker skin ([NHS](https://www.nhs.uk/pregnancy/keeping-well/pregnancy-vitamins-and-supplements/?ref=verinourishwomen.com)). National guidance differs, so if you are outside the UK, follow your own country's advice and your midwife or doctor. [Folic acid](https://verinourishwomen.com/supplements/folate/) reduces the risk of neural tube defects such as spina bifida, which form in the first few weeks. A Cochrane review of randomized trials found that folic acid, alone or with other vitamins and minerals, prevents neural tube defects, though it showed no clear effect on other birth defects ([Cochrane review, 2015](https://pmc.ncbi.nlm.nih.gov/articles/PMC8783750/?ref=verinourishwomen.com)). [Vitamin D](https://verinourishwomen.com/supplements/vitamin-d/) supports the baby's developing bones and your own, and shortfalls are common, especially in winter. A simple pregnancy multivitamin that contains both covers the essentials. There is no need to spend a fortune; the dose is what counts, not the brand. ## Folic acid: the timing is everything The neural tube forms and closes in the first weeks after conception, often before a pregnancy is confirmed. That is why folic acid is started early, ideally about three months before trying to conceive, and continued to the end of week 12. Most women take 400 micrograms a day. A higher 5 milligram dose is prescribed by a doctor for women at increased risk, for example with diabetes, certain blood conditions, some medicines such as epilepsy treatments, or a previous pregnancy affected by a neural tube defect ([NHS](https://www.nhs.uk/pregnancy/keeping-well/pregnancy-vitamins-and-supplements/?ref=verinourishwomen.com)). That higher dose is a medical decision, not something to self-prescribe. ![Timeline of pregnancy supplements. Folic acid, 400 micrograms a day, runs from about three months before trying to conceive and stops at the end of week 12. Vitamin D, 10 micrograms or 400 IU a day, runs throughout, in autumn and winter or year-round with little sun. A bracket marks the first weeks after conception, when the neural tube forms and closes, often before a pregnancy is confirmed. A higher 5 milligram folic acid dose is prescribed by a doctor for women at increased risk.](https://storage.ghost.io/c/57/09/5709dd99-0d8d-4e4f-a27f-18d807e14fbf/content/images/2026/09/folic-acid-timeline.webp) The neural tube closes before many women know they are pregnant, which is why folic acid starts before conception rather than after a positive test. ## What about iron and everything else A standard prenatal can cover folic acid and vitamin D. Beyond that, more is not automatically better. - **Iron advice differs by country.** In the UK, iron levels are checked during routine antenatal blood tests and supplements are usually recommended if you are low or anemic ([NHS](https://www.nhs.uk/pregnancy/keeping-well/pregnancy-vitamins-and-supplements/?ref=verinourishwomen.com)). WHO takes a population-level approach and recommends 30 to 60 mg of elemental iron daily, together with 400 micrograms of folic acid, for all pregnant women in settings that follow its guidance ([WHO, updated 2024](https://www.who.int/tools/elena/interventions/daily-iron-pregnancy?ref=verinourishwomen.com)). Do not add a separate iron tablet without checking the label of your prenatal and speaking to your midwife or doctor. Our guide to [iron in pregnancy](https://verinourishwomen.com/pregnancy/iron-in-pregnancy/) covers the dosing context; see also [iron](https://verinourishwomen.com/supplements/iron/), [iron deficiency](https://verinourishwomen.com/conditions/iron-deficiency/) and [iron-rich foods](https://verinourishwomen.com/nutrition/iron-rich-foods/). - **Omega-3 and calcium** are best met from food for most women. Oily fish, dairy, fortified foods and leafy greens do the work; see [calcium](https://verinourishwomen.com/supplements/calcium/) and [omega-3](https://verinourishwomen.com/supplements/omega-3/) for detail. - **Megadose multivitamins** aimed at pregnancy are unnecessary and can contain too much of some nutrients. A basic pregnancy supplement is enough. ## What to avoid A few things are worth steering clear of: - **Vitamin A (retinol) supplements**, including cod liver oil, and liver or liver products, because too much vitamin A can harm the baby ([NHS](https://www.nhs.uk/pregnancy/keeping-well/pregnancy-vitamins-and-supplements/?ref=verinourishwomen.com)). - **High-dose or unregulated supplements**, which can deliver amounts no one has checked for pregnancy. - **Herbal supplements**, unless your midwife or pharmacist has confirmed they are safe. ## When to start and how to keep it simple If you are planning a pregnancy, start folic acid now and add vitamin D. If you have only just found out you are pregnant, start both today; it is never too late to begin vitamin D, and folic acid still matters up to week 12\. In the UK, some families qualify for free vitamins through the Healthy Start scheme, so it is worth asking your midwife. Keep the routine easy: one pregnancy multivitamin with folic acid and vitamin D, taken at a time of day you will remember. If [morning sickness](https://verinourishwomen.com/pregnancy/morning-sickness/) makes swallowing a tablet hard, taking it with food or at a different time can help. Weight gain is the other thing your midwife will discuss early, because the recommended range depends on your pre-pregnancy BMI. Our [pregnancy weight calculator](https://verinourishwomen.com/tools/pregnancy-weight-calculator/) shows the range that applies to you. ## When to see your doctor or midwife Speak to a professional if you may be at higher risk and could need the 5 milligram folic acid dose, if you have a health condition or take regular medicines, or if you are unsure whether a supplement is safe. They can tailor the advice to you, which matters more than any label on a box. ## Frequently asked questions ### Which prenatal vitamins do I actually need? Two have strong evidence: folic acid, 400 micrograms a day from before conception through the first 12 weeks, and vitamin D, 10 micrograms (400 IU) a day through autumn and winter, or year-round if you get little sun. A simple pregnancy multivitamin that contains both covers the essentials for most women. You do not need a large stack of supplements. ### When should I start taking folic acid? Ideally about three months before trying to conceive, and at least from the moment you start trying, continuing until the end of week 12\. The neural tube forms very early, often before a pregnancy is confirmed, so starting early is what makes folic acid work. ### How much folic acid should I take? 400 micrograms a day for most women. A higher 5 milligram dose is prescribed by a doctor for people at increased risk, including those with diabetes, sickle cell anemia or thalassaemia, certain epilepsy or HIV medicines, or a personal or family history of a neural tube defect. Do not take the high dose without medical advice. ### What should I avoid in pregnancy supplements? Avoid supplements containing vitamin A (retinol), and liver or liver products, because too much vitamin A can harm the baby. Skip high-dose or unregulated products, and check any herbal supplement with your midwife or pharmacist before taking it. ### Do I need iron or omega-3 supplements in pregnancy? Iron advice depends on where you receive care. In the UK, blood tests are routine and iron is usually recommended when levels are low. WHO recommends 30 to 60 mg of elemental iron daily for all pregnant women in settings that follow its global guidance. Follow your national guidance and your midwife or doctor rather than adding a separate iron tablet yourself. Omega-3 and calcium are best met from food for most women. ## References 1. [Vitamins, supplements and nutrition in pregnancy](https://www.nhs.uk/pregnancy/keeping-well/pregnancy-vitamins-and-supplements/?ref=verinourishwomen.com) · NHS 2. [Effects and safety of periconceptional oral folate supplementation for preventing birth defects](https://pmc.ncbi.nlm.nih.gov/articles/PMC8783750/?ref=verinourishwomen.com) · Cochrane Database of Systematic Reviews, 2015 3. [Dietary supplements and life stages: pregnancy](https://ods.od.nih.gov/factsheets/Pregnancy-HealthProfessional/?ref=verinourishwomen.com) · NIH Office of Dietary Supplements 4. [Daily iron and folic acid supplementation during pregnancy](https://www.who.int/tools/elena/interventions/daily-iron-pregnancy?ref=verinourishwomen.com) · World Health Organization, updated 2024