Should You Take Vitamin D in Pregnancy? The NHS Advice, Explained

Yes. The NHS says that if you're pregnant "it's recommended you take: 10 micrograms of vitamin D every day between early October and late March", and all year if you cover most of your skin outside, are mostly indoors or have black or brown skin.¹ Its colecalciferol page gives the same amount as "400IU throughout pregnancy" and notes that "Many pregnancy multivitamins already contain 400IU (10 micrograms) of vitamin D", in which case "you will not need an extra vitamin D supplement".² The limit is 100 micrograms a day; higher doses are for a diagnosed deficiency through your midwife or GP.^{1, 3, 4} Part of the vitamin D guide in our vitamins and minerals guide.

Does the NHS recommend vitamin D in pregnancy?

It does, as one of two routine supplements. The NHS says vitamin D "helps your baby's bones and teeth develop", and that between early October and late March "we cannot make enough vitamin D from sunlight".¹ The other routine supplement is folic acid, "400 micrograms of folic acid every day" for the first 12 weeks; see folic acid during pregnancy.¹ The one warning: "Do not take cod liver oil or supplements containing vitamin A (sometimes called retinol) when you're pregnant", and avoid liver.¹

The NHS adds that "Women and children who qualify for the Healthy Start scheme can get free supplements containing vitamin D."³

How much vitamin D is too much in pregnancy?

The NHS sentence in full: "Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful. This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17 years."³ 5,000 IU (125 micrograms) is above it. 50,000 IU and 60,000 IU are not supplement amounts but the size of prescribed courses for a diagnosed deficiency, where the NHS says "your doctor or midwife may offer a higher dose of colecalciferol" with "extra blood tests".² If you have hypercalcaemia, kidney problems or kidney stones, or sarcoidosis, the NHS says to tell your doctor before starting.⁵ Contact 111 if "you have taken more than 4,000IU of colecalciferol in 1 day"; symptoms are on can you take too much vitamin D.⁶

Can I take vitamin D and a pregnancy multivitamin together?

Only after adding them up. The NHS line is "Check the packet to see what dose of vitamin D it contains."² A 10 microgram multivitamin plus a separate 25 microgram product makes 35 micrograms a day: within the limit but above the NHS figure, so ask a pharmacist. The colecalciferol page is stricter: "Do not take any other vitamin or mineral supplements that contain calcium or vitamin D without talking to your doctor first."⁷ The same rule covers anything else added in pregnancy, from collagen to medicines (what you should not take with vitamin D).

What have the trials of vitamin D in pregnancy found?

The UK MAVIDOS trial (2016). 1,134 women took 1,000 IU (25 micrograms) of colecalciferol or placebo daily from 14 weeks to delivery. Newborn whole-body bone mineral content did not differ (61.6 g against 60.5 g, p=0.21). Severe post-partum haemorrhage was less common with vitamin D (12% against 17%, p=0.01), "No adverse events were deemed to be treatment related", and the authors called 1,000 IU daily sufficient to keep most pregnant women replete, "and it is safe".⁸

The Cochrane review (2019). Across 30 trials and 7,033 women, vitamin D alone against placebo or nothing (22 trials, 3,725 women) "probably reduces the risk of pre-eclampsia" (risk ratio 0.48, 95% confidence interval 0.30 to 0.79; 4 trials, 499 women, moderate certainty) and gestational diabetes (0.51, 0.27 to 0.97; 4 trials, 446 women, moderate certainty), and "probably reduces the risk of having a baby with low birthweight" (0.55, 0.35 to 0.87; 5 trials, 697 women, moderate certainty). Vitamin D with calcium "may increase the risk of preterm birth" (1.52, 1.01 to 2.28; 5 trials, 942 women, low certainty).⁹ The NHS recommendation rests on the 10 microgram requirement, not on these outcomes.

The Bangladesh trial (2018). 1,300 pregnancies randomised to weekly 4,200 to 28,000 IU from 17 to 24 weeks, or placebo, showed no difference in infant length at one year (P=0.23): supplementation "did not improve fetal or infant growth", and the highest dose brought "a higher rate of possible hypercalciuria".¹⁰

When should I start taking vitamin D in pregnancy, and does the form matter?

The NHS wording is "throughout pregnancy", so start as soon as you know; starting later still counts.² Time of day is on the best time to take vitamin D.

On the form, the UK's Scientific Advisory Committee on Nutrition concluded in 2024 that "Both vitamin D2 and vitamin D3 increase blood 25(OH)D concentrations, and both forms prevent and treat vitamin D deficiency"; in daily-dose trials at 5 to 25 micrograms it read "an advantage of vitamin D3 over D2 in raising blood 25(OH)D concentration of about 8nmol per litre", while cautioning that "the difference in estimated effect between the 2 forms may not be reliable".¹¹ The NHS says of how vitamin D is converted: "All types of vitamin D work in this way."¹² What vitamin D2 is reports each head-to-head trial with its dosing pattern.

Do I need vitamin D when breastfeeding, and does my baby?

For you: "Everyone, including pregnant and breastfeeding women, should consider taking a daily supplement containing 10mcg of vitamin D during the autumn and winter months", and "You can take colecalciferol (vitamin D) while you are breastfeeding."^{2, 13} Only a prescribed very high dose "(over 6,000IU a day)" means "your baby may need extra blood tests".²

Your supplement does not cover the baby: "Babies who are being breastfed should be given a daily vitamin D supplement from birth, whether or not you're taking a supplement containing vitamin D yourself", at "8.5 to 10 micrograms". A baby "having more than 500ml (about a pint) of infant formula a day" should not be given one, and never two products at once: "do not give them cod liver oil and vitamin drops because cod liver oil also contains vitamins A and D."⁴ Your health visitor can say where to get drops; age bands to 17: how much vitamin D babies and children need.

Who is at higher risk of low vitamin D in pregnancy?

Pregnancy is itself on the NHS list. You "may be at higher risk of vitamin D deficiency" if you are 65 or older, "have low or no exposure to the sun", "have brown or black skin", have a malabsorption disorder, severe liver or end-stage kidney disease, take certain medicines, or "are pregnant or breastfeeding".¹² The pregnancy page adds: "If you think you might not get enough vitamin D, talk to a midwife or GP for advice."¹

In 2019 to 2023, 16.6% of women aged 19 to 64 had blood 25(OH)D below 25 nmol/L, the level below which population risk of poor musculoskeletal health rises (NDNS Table 6.9); by season, across 2016 to 2023, that was 2.2% of women in July to September and 29.2% in January to March (Table 6.15).¹⁴ The NHS symptom list is on signs of vitamin D deficiency.

Frequently asked questions

Can low vitamin D cause miscarriage?

None of the three studies above reported miscarriage as an outcome, and the NHS pregnancy pages do not link the two. Ask your midwife or GP; bleeding or pain in pregnancy means contacting your maternity unit the same day.

Can too much vitamin D harm my unborn baby?

The NHS warns that too many vitamin D supplements "over a long period of time can cause too much calcium to build up in the body (hypercalcaemia)".³ The Committee on Toxicity agreed that the 100 microgram limit "was appropriate for pregnant and lactating women", and said that for the heaviest supplement users the risk of raised blood or urinary calcium "cannot be completely excluded, especially in a few sensitive individuals".¹⁵ Stay at the NHS figure unless a clinician has prescribed more.

Is 1,000 IU of vitamin D safe in pregnancy?

1,000 IU is 25 micrograms, a quarter of the NHS limit, and the dose MAVIDOS gave 565 women from 14 weeks with no treatment-related adverse events.^{3, 8} The NHS everyday figure is 10 micrograms, which it says "will be enough for most people"; that is the recommendation unless a midwife or GP sets another.³

What happens if I do not take vitamin D in pregnancy?

The NHS says "A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults."³ UK surveillance in 2015 to 2017 found 125 cases of nutritional rickets in under-16s (0.48 per 100,000 a year), 116 of them under five and mostly Black or South Asian; 77.6% "were not taking vitamin D supplements despite being eligible".¹⁶ The 10 microgram supplement and the baby's drops are how the NHS closes that gap.

Sources

1. NHS. Pregnancy vitamins and supplements. Reviewed 3 June 2026. nhs.uk.
2. NHS. Colecalciferol: pregnancy, breastfeeding and fertility. Reviewed 10 January 2023. nhs.uk.
3. NHS. Vitamin D. Reviewed 3 August 2020. nhs.uk.
4. NHS. Vitamins for children. Reviewed 30 May 2024. nhs.uk.
5. NHS. Who can and cannot take colecalciferol. Reviewed 10 January 2023. nhs.uk.
6. NHS. How and when to take colecalciferol. Reviewed 10 January 2023. nhs.uk.
7. NHS. Colecalciferol with other medicines and supplements. Reviewed 10 January 2023. nhs.uk.
8. Cooper C, et al. Maternal gestational vitamin D supplementation and offspring bone health (MAVIDOS). Lancet Diabetes & Endocrinology, 2016. PubMed 26944421.
9. Palacios C, et al. Vitamin D supplementation for women during pregnancy. Cochrane Database of Systematic Reviews, 2019. PubMed 31348529.
10. Roth DE, et al. Vitamin D supplementation in pregnancy and lactation and infant growth. New England Journal of Medicine, 2018. PubMed 30089075.
11. SACN. Fortifying foods and drinks with vitamin D: summary, 23 May 2024. gov.uk.
12. NHS. Common questions about colecalciferol. Reviewed 10 January 2023. nhs.uk.
13. NHS. Breastfeeding and diet. Reviewed 15 May 2026. nhs.uk.
14. National Diet and Nutrition Survey 2019 to 2023 (Tables 6.9 and 6.15). gov.uk.
15. COT for SACN. Statement on excess vitamin D intake during preconception, pregnancy and lactation. gov.uk.
16. Julies P, et al. Nutritional rickets under 16 years: UK surveillance results. Archives of Disease in Childhood, 2020. PubMed 31949032.