Vitamin D and Contraception: Unveiling the Link Between Estrogen-Based Pills and Vitamin D Levels
Vitamin D's connection to birth control methods unearthed
In a fascinating new research, scientists have discovered a connection between estrogen-based birth control pills and vitamin D levels in women. Women who are currently taking these contraceptives have higher quantities of vitamin D circulating in their bodies, while those who stop using them experience a significant drop in vitamin D levels.
Vitamin D plays a crucial role in maintaining healthy calcium and phosphorous levels in the blood, and it aids the body in absorbing calcium, a vital component of our bones. Apart from foods like fish and eggs, about 90% of our vitamin D comes from sunlight exposure, where a chemical reaction occurs in the skin.
Vitamin D deficiency can lead to severe health issues such as rickets in children and osteomalacia in adults (softening of the bones). Given its importance in bone formation, particularly during pregnancy, vitamin D deficiency can pose a significant risk.
Dr. Quaker E. Harmon, from the National Institutes of Health's National Institute of Environmental Health Sciences in Research Triangle Park, NC, decided to delve deeper into this phenomenon.
Investigating Vitamin D and Contraception
Dr. Harmon and her team conducted a cross-sectional analysis of data from the Study of Environment, Lifestyle, and Fibroids (SELF), a research project focusing on reproductive health. The study included 1,662 African-American women aged 23-34, living in and around Detroit, MI. Theyquestioned the women about their contraceptive use and time spent outside, along with any vitamin D supplements they took. Blood samples were collected to measure levels of 25-hydroxy vitamin D, the most common form of circulating vitamin D.
The study found that women who were using contraception containing estrogen had higher vitamin D levels compared to other women. After considering confounding factors such as seasonal exposure to light, the effect remained significant. Dr. Harmon's team could not find any behavioral differences, like increased time spent outdoors, to explain the increase.
Adjusting for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with roughly 20% higher levels of 25-hydroxy vitamin D. Current users of birth control had higher levels of vitamin D, while past users had average vitamin D levels.
Vitamin D Deficiency in Early Pregnancy
The findings, published in the Journal of Clinical Endocrinology & Metabolism, suggest that as a woman starts trying to become pregnant, she may be at risk of developing vitamin D deficiency. Dr. Harmon advises women planning to stop using birth control to take steps to ensure their vitamin D levels are adequate while trying to conceive and during pregnancy.
When asked about the reason for this association between estrogen-based contraception and vitamin D levels, Dr. Harmon stated, "While we do not know why vitamin D levels are higher, other work suggests that levels of other vitamin D metabolites are changed when women use estrogen-containing contraception. This suggests that there may be alterations in the metabolism of vitamin D. Further work is needed."
While the current study focused solely on African-American women, Dr. Harmon believes this association is not related to race. African-American women are more likely to be vitamin D-deficient in the United States, so even small increases or decreases in their vitamin D concentrations might be significant.
Dr. Harmon is also continuing to follow this group of women to further investigate the relationship and is working on another group of participants to explore how vitamin D varies across the menstrual cycle.
- The study conducted by Dr. Harmon revealed a connection between estrogen-based birth control pills and Vitamin D levels in women, with current users having higher levels compared to non-users.
- Vitamin D, crucial for maintaining healthy calcium and phosphorous levels, aids the body in absorbing calcium, a vital component of bones.
- Despite foods like fish and eggs being sources, about 90% of our Vitamin D comes from sunlight exposure, where a chemical reaction occurs in the skin.
- The research team found that women who were using contraception containing estrogen had higher Vitamin D levels compared to other women, even when considering confounding factors like seasonal exposure to light.
- Adequate Vitamin D levels are essential for women planning to stop using birth control, particularly during pregnancy, given Vitamin D's importance in bone formation.
- Dr. Harmon's future studies aim to further investigate the relationship between estrogen-based contraception and Vitamin D levels, exploring how it varies across the menstrual cycle and not limiting the study to specific cultural groups.
