Hidden connection discovered between vitamin D and contraceptive methods
Birth Control and Vitamin D
Taking estrogen-based birth control pills boosts the levels of vitamin D in women, while discontinuing these pills results in a significant drop. Vitamin D plays a crucial role in maintaining the proper levels of calcium and phosphorus in the blood, helping the body absorb calcium, an essential component of bones.
Although food sources like fish and eggs contain high amounts of vitamin D, approximately 90% of it is produced in the skin through a chemical reaction after sunlight exposure. Deficiency in vitamin D can lead to bone diseases like rickets and osteomalacia. Given that vitamin D is vital during pregnancy to support the growth of the fetal skeleton, it's essential, especially during pregnancy.
Dr. Quaker E. Harmon, from the National Institutes of Health's National Institute of Environmental Health Sciences in Research Triangle Park, NC, conducted a study on the association between vitamin D levels and contraception.
Contraception and Vitamin D
The research involved a cross-sectional analysis of data from the Study of Environment, Lifestyle, and Fibroids (SELF), a reproductive health investigation. It used almost 1,700 African-American women aged 23-34 living in and around Detroit, MI.
The study focused on contraceptive usage, time spent outdoors, and vitamin D supplement intake. In total, blood samples from 1,662 women were analyzed to measure the most common circulating form of vitamin D, called 25-hydroxy vitamin D.
According to the study, women using oral contraceptives containing estrogen tend to have higher vitamin D levels than other women. Even after controlling for confounding factors such as seasonal sunlight exposure, the effect remained significant.
"Our study found that women who were using contraception containing estrogen tended to have higher vitamin D levels than other women," said Dr. Harmon. "Our findings suggest that contraceptives containing estrogen tend to boost vitamin D levels, and those levels are likely to fall when women cease using contraception."
Adjusting for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with an approximate 20 percent higher level of 25-hydroxy vitamin D.
Current users of birth control displayed higher vitamin D levels, while past users had average vitamin D levels.
Vitamin D Deficiency in Early Pregnancy
This study's findings suggest that women attempting pregnancy run the risk of becoming deficient in vitamin D due to discontinuing contraception. To avoid this, Dr. Harmon recommends ensuring adequate vitamin D levels during the conception phase and pregnancy for women planning to stop using birth control.
Medical News Today asked Dr. Harmon why estrogen-based contraception might affect vitamin D levels, and she said that while she is unclear about the specific mechanisms, other work suggests that the levels of other vitamin D metabolites may change when women use estrogen-containing contraception, indicating potential alterations in the metabolism of vitamin D.
Dr. Harmon also mentioned that the research only focused on African-American women, but the same association has been observed in women of different ethnicities, suggesting that the relationship may not be race-related. Since African-American women in the United States are more likely to be vitamin D-deficient, even small increases or decreases in their vitamin D concentrations can have significant implications.
Dr. Harmon continues to investigate this relationship with the same group of women and plans to delve deeper into the relationship by studying another group of participants to explore how vitamin D varies across the menstrual cycle.
Learn more about research that shows higher vitamin D levels can lower cancer risk.
- The study conducted by Dr. Quaker E. Harmon focused on the association between vitamin D levels and contraception, specifically in African-American women.
- The research found that women using oral contraceptives containing estrogen have higher vitamin D levels compared to other women.
- The effect of higher vitamin D levels in women using estrogen-based contraception remained significant even after controlling for confounding factors like seasonal sunlight exposure.
- The study suggests that discontinuing contraception could potentially lead to vitamin D deficiency in women attempting pregnancy.
- Dr. Harmon recommends ensuring adequate vitamin D levels during the conception phase and pregnancy for women planning to stop using birth control.
- Other studies have observed the same association between vitamin D levels and contraception in women of different ethnicities, suggesting that the relationship may not be race-related.
