Low Vitamin D Levels Increase the Risk of Caesarian Section

The rate of births by caesarian section is on the rise, and researchers have begun to speculate if this may be related to widespread vitamin D deficiencies in industrialized countries. In the United States the caesarian birth rate is at an all time high of 30%, as compared to just 5% in 1970. Although the reasons for caesarians are varied, the role played by vitamin D in both skeletal and muscular strength may be an important factor.

Of the 253 women included in the study 43 (17%) delivered by primary caesarian section. The researchers found that 28% of women with very low serum vitamin D levels (less than 37 nmol/L) had caesarian sections, as compared with only 14% of women with levels higher than 37 nmol/L. When corrected for other factors it was determined that women with vitamin D deficiency were almost 4 times more likely to deliver via caesarian section than those who were not deficient.

Vitamin D deficiency has been associated with muscle weakness as well as reduced muscle performance and strength – which could contribute to the increased caesarian risk. Furthermore, low vitamin D levels may also increase the risk of preeclampsia. Finally, calcium levels have been associated with the initiation of labour. Since vitamin D is critical for calcium homeostasis, it is possible that vitamin D levels may also play a vital role in the initiation of labour.

It has been reported that up to 50% of mothers and 65% of infants are deficient at the time of birth, even when the mothers had been supplementing with 400IU of vitamin D. The results of this, and other studies, emphasize the critical importance of maintaining adequate vitamin D levels during pregnancy.

Merewood A, Mehta SD, Chen TC, Bauchner H, Holick MF. Association between vitamin D deficiency and primary caesarian section. J Clin Endocrinol Metab. 2009. 94(3): 940-945.