Vitamin D deficiency in pregnant women from a non-European ethnic minority population--an interventional study.

OBJECTIVE: To determine the vitamin D status of pregnant women from non-European ethnic minorities in South Wales.
DESIGN: Prospective study.
SETTING: Llandough Hospital, Cardiff, South Wales. SAMPLE: One hundred and sixty pregnant women from a non-European ethnic minority population in South Wales.
METHODS: Biochemical screening of vitamin D status was carried out at the first antenatal visit. Women found to be deficient in vitamin D were subsequently supplemented and vitamin D status was rechecked at delivery. MAIN OUTCOME MEASURE: Vitamin D status at delivery.
RESULTS: Eighty of 160 women had a vitamin D level below 8 ng/mL at their first antenatal visit and were treated with oral vitamin D. Factors that could influence vitamin D status such as religion, fluency in English and dressing habits did not appear to have any effect, although a higher proportion of women who had lived in Britain for longer than three years had subnormal vitamin D levels. In 58 of those checked at delivery, the mean plasma vitamin D level increased from 6 to 11 ng/mL although the mean parathyroid hormone level was unchanged.
CONCLUSION: In view of the high incidence of subnormal vitamin D levels in women from ethnic minorities, we recommend biochemical screening of these women in early pregnancy, with subsequent supplementation where indicated.