A recent study out of China has found that pregnant women in Beijing are at high risk for vitamin D deficiency.
Women living in Beijing, China, are more susceptible to vitamin D deficiency because of both environmental and cultural factors. The air in Beijing has become very polluted in recent years. Air pollution inhibits UVB rays to some degree of reaching the ground surface. Additionally, Chinese women tend to avoid sun exposure, as fairer and lighter skin is the cultural preference.
Researchers in the present study wanted to examine how these factors affect the vitamin D status of pregnant women living in Beijing during winter. They gathered data from 125 healthy pregnant women between 15 and 20 weeks gestation. They surveyed these women on lifestyle factors as well as acquired a blood sample to measure their vitamin D levels.
They found that all of the women in the participant group had vitamin D levels less than 30 ng/ml. Forty-five percent of the women had levels less than 10 ng/ml, and 52% of the women had levels between 10 and 20 ng/ml.
Among the participants, 58 of the women reported taking multivitamin supplements. The vitamin D content of the multivitamins ranged from 200 to 500 IU. Those who took a multivitamin had lower risk of having a level under 10 ng/ml, with 22.4% of those taking a multivitamin having levels less than 10 ng/ml compared to 64.2% among those not taking multivitamins.
The researchers noted that because the participants all live in Beijing, the results cannot be generalized to rural populations. Additionally, they didn’t gather dietary information, meaning that they cannot factor in diet as contributing to their results.
“To our knowledge, this study is the first to report the influence of maternal factors on vitamin D status in Chinese pregnant women,” the researchers stated. “Importantly, we did have the information on multivitamin supplement usage, which allowed us to show that while pregnancy-specific multivitamin supplements improve the status in women at low risk of severe vitamin D deficiency, it does not prevent women from vitamin D deficiency in winter.”