Endocrine Abstracts

Objective: To determine the vitamin D status in pregnancy and to evaluate the effects of daily and of single-dose vitamin D supplementation.

Design: A prospective randomised study, in an inner city ante-natal clinic.

Participants: Forty-five women in each of the four ethnic groups, Indian Asians, Middle Eastern, Black and Caucasian, were studied (incomplete delivery data at time of submission).

Intervention: Women were randomised into three treatment groups: a single oral dose of 200,000 IU vitamin D, a daily supplement of 800 IU vitamin D from 27 weeks until delivery and a no treatment group.

Results: At 27 weeks gestation, there was a significantly lower concentration of vitamin D levels in Asian (25+10 nmol/l), Middle Eastern (21+9 nmol/l) and Black (23+13 nmol/l) compared to the Caucasian group (42+17 nmol/l); P<0.001. Secondary hyperparathyroidism (PTH levels >6.8 pmol/l; n=46) was significantly higher in Asian (26.7%), Middle Eastern (48.9%) and Black women (24.4%) compared to Caucasian women (2.2%); P<0.05. All ethnic groups had normal calcium levels at 27 weeks and at delivery. Significant predictors of Vitamin D levels at 27 weeks are ethnic group, age, parity and daily sunlight exposure greater than 2 hours. There was a significant increase in the maternal vitamin D concentration in the supplemented group (daily 42+12, stat dose 34+13 vs 27+14 nmol/l in the no treatment; P<0.01) and cord vitamin D concentration (daily 27+14, stat dose 26+13 vs 17+14 nmol/l in the no treatment; P<0.0001). There was no significant difference in the method of supplementation.

Conclusion: Vitamin D levels were significantly lower in Asian, Middle Eastern and Black women compared to Caucasian. Women may potentially benefit from vitamin D supplementation in pregnancy, which can be achieved with a single dose at 27 weeks gestation.