Discovered connection between vitamin D and contraception revealed
Women's Vitamin D Levels and Contraceptives: A New Connection
Turns out, estrogen-based birth control pills may be affecting your vitamin D levels more than you might think. Researchers have discovered that women who are on these contraceptives have a higher quantity of circulating vitamin D, while those who stop using them face a significant drop in vitamin D levels.
Vitamin D, often dubbed the 'sunshine vitamin,' plays a crucial role in maintaining the correct calcium and phosphorous levels in the blood. It also aids the body in absorbing calcium, a fundamental component of bones. While food sources such as fish, eggs, and fortified dairy products are high in vitamin D, around 90 percent of it is produced in the skin through a chemical reaction after exposure to sunlight.
Deficiency in vitamin D can result in dreadful conditions like rickets and osteomalacia (softening of the bones). Given its significance in bone formation, it's particularly vital during pregnancy.
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 into the changes in vitamin D levels connected with taking oral contraceptives.
Vitamin D and Contraception
The researchers performed a cross-sectional analysis of data from the Study of Environment, Lifestyle, and Fibroids (SELF), an investigation of reproductive health. The project involved nearly 1,700 African-American women aged 23-34 living in and around Detroit, MI.
The study questioned women about their contraceptive use and included details about the amount of time they spent outside and any vitamin D supplements they took. A total of 1,662 women provided blood samples to ascertain their levels of the most common circulating form of vitamin D, called 25-hydroxy vitamin D.
During pregnancy, women produce increased levels of the active form of vitamin D to support the growth of the fetal skeleton. Consequently, pregnant women have an increased risk of vitamin D deficiency and, therefore, a heightened risk of developing bone problems.
"Our study found that women using contraception containing estrogen tended to have higher vitamin D levels than other women," said Dr. Harmon. Even after controlling for confounding factors such as seasonal exposure to light, the effect remained significant. "We could not find any behavioral differences such as increased time spent outdoors to explain the increase," added 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."
After adjustments for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with 20 percent higher levels of 25-hydroxy vitamin D. Current users of birth control had higher levels of vitamin D, while past users had average levels.
Vitamin D Deficiency in Early Pregnancy
These findings, published this week in the Journal of Clinical Endocrinology & Metabolism, suggest that as a woman starts trying to become pregnant, she runs the risk of becoming deficient in vitamin D. Dr. Harmon advises, "For women who are planning to stop using birth control, it is worth taking steps to ensure that vitamin D levels are adequate while trying to conceive and during pregnancy."
Medical News Today asked Dr. Harmon why estrogen-based contraception might affect vitamin D levels, and she noted, "We do not know why vitamin D levels are higher. Other work suggests that the 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."
Dr. Harmon also stated that she is continuing to follow this group of women to further investigate the relationship. In addition, she is working on another group of participants to examine how vitamin D varies across the menstrual cycle.
It's essential to note that this study focused solely on African-American women. Regarding the role of race in this effect, Dr. Harmon suggested, "The same association has been observed in young and older women who are not African-American, so we believe this association is not related to race. In the United States, African-American women are more likely to be vitamin D-deficient, so small increases or decreases in their vitamin D concentrations may be more important."
Overall, while the specific mechanism of how estrogen-based contraceptives affect vitamin D levels remains unclear, it's crucial to maintain adequate vitamin D levels for overall health, particularly during pregnancy. More research is needed to clarify the effects of estrogen-based contraceptives on vitamin D levels and potential racial differences in these effects.
- Women on estrogen-based contraceptives may have higher vitamin D levels than those who cease their use, as suggested by the study involving nearly 1,700 African-American women.
- The study, published in the Journal of Clinical Endocrinology & Metabolism, found that current users of hormonal contraception had higher levels of vitamin D, while past users had average levels.
- Dr. Harmon, the study's lead researcher, noted that while estrogen-based contraception might affect vitamin D levels, the specific mechanism remains unclear.
- As women plan to stop using birth control, it is advisable for them to ensure vitamin D levels are maintained adequately, as deficiencies can lead to conditions like rickets and osteomalacia during pregnancy.
- Further research is needed to clarify the effects of estrogen-based contraceptives on vitamin D levels and potential racial differences in these effects, as the current study only focused on African-American women.
- It is essential to maintain adequate vitamin D levels for overall health, particularly during pregnancy, given its significance in bone formation and the increased risk of deficiency during this period.
