A recently published article by Mumford et al 1 showed that sufficient preconception vitamin D levels (25-hydroxyvitamin D ≥75 nmol/L) are associated with an increased likelihood of pregnancy and livebirth.

The team also found that Increased vitamin D concentrations before conception were associated with reduced pregnancy loss.

Quick study summary

The study was a secondary analysis of a cohort of 1191 women that were already enrolled into a trial looking at the effects of aspirin on gestation and reproduction (The EAGeR trial2).

This group of women aged 18–40 years, with one to two previous pregnancy losses, were recruited at four clinical sites in the USA and followed up for up to six menstrual cycles while attempting pregnancy and throughout pregnancy if they conceived.

Their Vitamin D levels were measured preconception and at 8 weeks gestation. The researchers then looked at outcomes of clinical pregnancy, time to pregnancy, pregnancy loss and livebirths.

The study results

Of the 1191 women that had available data on preconception 25-hydroxyvitamin D concentrations, 555 (47%) women were classified as having sufficient concentrations (≥75 nmol/L) and 636 (53%) as having insufficient concentrations (<75 nmol/L).

Women with sufficient preconception 25-hydroxyvitamin D were on average 10% more likely to achieve clinical pregnancy (adjusted RR 1·10 [1·01–1·20]) and 15% more likely to have a livebirth (1·15 [95% CI 1·02–1·29]) than women with insufficient concentrations.

Amongst women who achieved pregnancy, sufficient preconception 25-hydroxyvitamin D was associated with a 12% reduced risk of pregnancy loss per 25nmol/L (preconception RR per 25 nmol/L 0·88 [95% CI 0·77–0·99].

Take home messages

Women with a history of miscarriage are more likely to become pregnant and give birth to a healthy infant when preconception levels of vitamin D are sufficient.

And the other interesting thing to note was how more than half of the group studied had low concentrations of Vitamin D.

What is your vitamin D level?

Chances are that you aren’t aware what your vitamin D level is. Currently vitamin D levels are not routinely checked in the UK (whether trying to conceive or not) and the advice from Public Health England is to take a 10mcg vitamin D supplement daily (especially during the winter months) as exposure to the sun is not deemed sufficient enough to produce adequate levels of vitamin D.

Should women trying to conceive check their vitamin D levels?

Data shows that at least 1 in 5 people in the UK have low vitamin D levels, so it is arguable following the results of this latest study that if you’re trying to conceive (especially if you’ve suffered previous miscarriages) it might well be worth having your vitamin D level checked.

A regular 10mcg supplement is safe and recommended during pregnancy but it might be useful to know what your preconception level is and supplement it adequately prior to conception.

At RoC we can check your vitamin D levels and advise you on suitable supplementation prior to conception, as well as support you throughout your pregnancy in one of our pregnancy clinics.

Antenatal care at RoC Private Clinic

RoC runs pregnancy clinics on both the Aberdeen and London sites, including:

  • Rapid Access to Appointments, usually same day or within 24 hours
  • Best medical monitoring technology
  • Antenatal Health Screening (history, examination, pre-pregnancy advice, urine and blood tests, scanning arrangements)
  • Post-delivery Support Service to new mothers regarding feeding and breastfeeding issues
  • Harmony Testing from 11 weeks of pregnancy onwards, with results ready within 5 working days
  • Baby Scans

Don’t hesitate to contact us for more information.


  1. Mumford, Sunni & A Garbose, Rebecca & Kim, Keewan & Kissell, Kerri & L Kuhr, Daniel & R Omosigho, Ukpebo & Perkins, Neil & Galai, Noya & M Silver, Robert & Sjaarda, Lindsey & Plowden, Torie & Schisterman, Enrique. (2018). Association of preconception serum 25-hydroxyvitamin D concentrations with livebirth and pregnancy loss: a prospective cohort study. The Lancet Diabetes & Endocrinology. 10.1016/S2213-8587(18)30153-0.
  2. Connell, Matthew & Sjaarda, Lindsey & Radin, Rose & Kuhr, Daniel & Mumford, Sunni & Plowden, Torie & M. Silver, Robert & Schisterman, Enrique. (2017). The Effects of Aspirin in Gestation and Reproduction (EAGeR) Trial: A Story of Discovery. Seminars in Reproductive Medicine. 35. 344-352. 10.1055/s-0037-1606384.

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