New study reveals possible connection between vitamin D levels and hormonal contraceptives
Women who use estrogen-based birth control pills may have 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. Conversely, women who discontinue estrogen-based contraceptives could experience a significant drop in vitamin D levels.
Vitamin D plays a pivotal role in maintaining proper calcium and phosphorous levels in the blood. It also aids in the absorption of calcium, an essential component of bones. Food sources rich in vitamin D include fish and eggs, but most of the vitamin is produced in the skin through sunlight exposure.
Vitamin D deficiency can lead to conditions like rickets and osteomalacia, which cause the softening of bones. Given vitamin D's importance in bone formation, it is especially crucial during pregnancy.
Dr. Harmon and her team investigated any potential connections between vitamin D levels and oral contraceptive use by analyzing data from the Study of Environment, Lifestyle, and Fibroids (SELF), a project focused on reproductive health. The researchers analyzed the information of nearly 1,700 African-American women aged 23-34 living near Detroit, MI, asking about their contraceptive use and sun exposure habits. In total, 1,662 women provided blood samples to determine their levels of 25-hydroxy vitamin D, the most common circulating form of the vitamin.
The study found that women using estrogen-based contraceptives generally had higher vitamin D levels than other participants, even after accounting for confounding factors like seasonal exposure to light. Dr. Harmon explained that her team could not identify any behavioral differences, such as increased sunlight exposure, to explain the increase in vitamin D levels among women using estrogen-based contraceptives.
After adjusting for potential confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with 20 percent higher levels of 25-hydroxy vitamin D. According to the researchers, current users of estrogen-based contraception had higher levels of vitamin D, while past users had average levels.
As women planning to become pregnant might be at risk of vitamin D deficiency after stopping birth control use, Dr. Harmon advised taking steps to maintain adequate vitamin D levels during conception and pregnancy. The researchers' findings were published this week in the Journal of Clinical Endocrinology & Metabolism.
The study focused solely on African-American women, and Dr. Harmon noted that small increases or decreases in vitamin D concentrations in this population may have a substantial impact. However, similar associations have been observed in women not of African descent, suggesting that the association between estrogen-based contraceptives and vitamin D levels may not be specific to race.
Dr. Harmon is continuing to follow the study participants to further investigate the relationship between estrogen-based contraceptives and vitamin D levels. Additionally, she is working on a second group to examine how vitamin D levels vary across the menstrual cycle.
While the study provides insight into the relationship between estrogen-based contraceptives and vitamin D levels, researchers emphasize the importance of maintaining adequate vitamin D levels during pregnancy for both maternal and fetal health.
- The study led by Dr. Harmon indicates that women using estrogen-based contraceptives may have higher levels of vitamin D, crucial for maintaining proper calcium and phosphorous levels in the blood.
- Food sources of vitamin D include fish and eggs, but the vitamin is primarily produced in the skin through sunlight exposure.
- Conversely, women who discontinue estrogen-based contraceptives could experience a significant drop in vitamin D levels, which might lead to conditions like rickets and osteomalacia.
- Given vitamin D's role in bone formation and its importance during pregnancy, women planning to become pregnant may be at risk of vitamin D deficiency after stopping birth control use.
- The study, published in the Journal of Clinical Endocrinology & Metabolism, focused solely on African-American women, but similar associations have been observed in women not of African descent.
- To maintain adequate vitamin D levels during conception and pregnancy, women are advised to take steps centered around health-and-wellness and nutrition, particularly focusing on women's vitamins.
