New study finds potential link between vitamin D levels and birth control efficacy
Women using estrogen-based contraceptives may experience higher levels of circulating vitamin D, according to a new study led by Dr. Quaker E. Harmon from the National Institutes of Health's National Institute of Environmental Health Sciences. The research, published in the Journal of Clinical Endocrinology & Metabolism, indicates that those who stop using such contraceptives face a significant drop in vitamin D levels.
Vitamin D plays a crucial role in maintaining the correct calcium and phosphorus levels in the blood and facilitating bone growth. While food sources like fish and eggs are rich in vitamin D, about 90% of the vitamin is produced in the skin through sunlight exposure.
Deficiencies in vitamin D can lead to health issues such as rickets and osteomalacia. Given its importance in bone formation, it is particularly critical during pregnancy. Dr. Harmon and her team decided to investigate any changes in vitamin D levels associated with taking oral contraceptives.
The researchers analyzed data from the Study of Environment, Lifestyle, and Fibroids (SELF), which included over 1,600 African-American women aged 23-34 living in Detroit, MI. The study asked participants about their contraceptive use, outdoor activity, and any vitamin D supplements they took. The women provided blood samples to measure their 25-hydroxy vitamin D levels, the most common circulating form of vitamin D.
The study found that women who were using contraceptives containing estrogen tended to have higher vitamin D levels than other participants. After adjusting for confounding factors, such as seasonal light exposure, the effect remained significant, with current users of birth control showing a 20% increase in 25-hydroxy vitamin D levels compared to non-users.
The increased vitamin D levels during estrogen-based contraceptive use can stem from various factors, including estrogen's influences on vitamin D metabolism, hormonal balance, and potential lifestyle or dietary differences in women using contraceptives. Conversely, stopping contraceptive use can lead to lower vitamin D levels due to the loss of estrogen's effects and possible changes in lifestyle or diet.
The findings suggest that women who are planning to stop using birth control should take steps to ensure adequate vitamin D levels during pregnancy, a time when adequate vitamin D levels are particularly important due to the increased risk of deficiency and related bone problems. The study only involved African-American women, with Dr. Harmon expressing the belief that the association may not be related to race as similar associations have been observed in non-African-American women. She will continue to follow this group of women and work on another group to investigate how vitamin D varies across the menstrual cycle.
- For women using estrogen-based contraceptives, higher levels of circulating vitamin D may occur, according to a study led by Dr. Quaker E. Harmon.
- This research, published in the Journal of Clinical Endocrinology & Metabolism, indicates that those who stop using such contraceptives face a significant drop in vitamin D levels.
- Given the importance of vitamin D in women's health and bone formation, investigating any changes in vitamin D levels associated with taking oral contraceptives is critical.
- The study found that women using contraceptives containing estrogen tended to have higher vitamin D levels than other participants, with current users showing a 20% increase in 25-hydroxy vitamin D levels compared to non-users.
- The increased vitamin D levels during estrogen-based contraceptive use can stem from various factors, including estrogen's influences on vitamin D metabolism, hormonal balance, and potential lifestyle or dietary differences in women using contraceptives.
- As women planning to stop using birth control should take steps to ensure adequate vitamin D levels during pregnancy, particularly due to the increased risk of deficiency and related bone problems, further research is needed to investigate how vitamin D varies across the menstrual cycle in different populations.
