Vitamin D's surprising connection to birth control revealed
Study Reveals Connection Between Estrogen-Based Birth Control and Vitamin D Levels
Researchers have discovered a link between women using estrogen-based birth control pills and higher levels of vitamin D in their circulation. Conversely, those who discontinue using such contraceptives may experience a significant drop in their vitamin D levels.
Vital for maintaining the correct balance of calcium and phosphorus in the blood, vitamin D also facilitates the body's absorption of calcium, a crucial component of bones. Rich sources of vitamin D include fish and eggs, while approximately 90% of the vitamin is produced naturally in the skin upon exposure to sunlight.
Vitamin D deficiency can result in conditions such as rickets and osteomalacia, which involve the softening of bones. Since vitamin D plays a significant role in bone formation, it is particularly important during pregnancy.
Dr. Quaker E. Harmon, of the National Institutes of Health's National Institute of Environmental Health Sciences in Research Triangle Park, NC, led the investigation into any changes in vitamin D levels associated with taking oral contraceptives.
Examining the Relationship Between Vitamin D and Contraception
The researchers conducted a cross-sectional analysis using data from the Study of Environment, Lifestyle, and Fibroids (SELF). The project involved almost 1,700 African-American women aged 23-34 residing in and around Detroit, MI. The study asked women about their contraceptive use and included questions about their time spent outdoors and any vitamin D supplements they took.
In total, 1,662 women provided blood samples to determine levels of the most common circulating form of vitamin D, known as 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. As a result, pregnant women are at a higher risk of vitamin D deficiency and, consequently, a heightened risk of developing bone problems.
"Our study found that women who were using contraception containing estrogen tended to have higher vitamin D levels than other women," stated Dr. Harmon. Even after controlling for potential 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," Dr. Harmon added. "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 adjusting for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with 20% higher levels of 25-hydroxy vitamin D. Current users of birth control displayed higher levels of vitamin D, while past users had average vitamin D levels.
Vitamin D Deficiency in Early Pregnancy
Published this week in the Journal of Clinical Endocrinology & Metabolism, these findings suggest that as a woman begins trying to conceive, she may be at risk of becoming deficient in vitamin D. Dr. Harmon offers advice for women planning to stop using birth control:
"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 to explain the possible reasons for estrogen-based contraception's impact on vitamin D levels, and she explained that more research is needed to clarify this relationship. Additionally, she noted that the study only involved African-American women, but the same association has been observed in other populations, implying that race may not be a significant factor in this effect.
Dr. Harmon also plans to continue following this group of women to further investigate the relationship between estrogen-based contraceptives and vitamin D levels, as well as working on a new group of participants to investigate how vitamin D varies across the menstrual cycle.
- This study revealed a connection between estrogen-based contraceptives and higher vitamin D levels in women, with a significant drop observed upon discontinuation.
- Since vitamin D is crucial for maintaining bone health, particularly during pregnancy, this discovery might have implications for women's health and wellness.
- In their investigation, researchers found that oral contraceptive use was associated with 20% higher levels of the most common form of vitamin D, 25-hydroxy vitamin D.
- As a woman begins trying to conceive, she may be at risk of becoming deficient in vitamin D, given the boost in vitamin D levels while using estrogen-based contraception.
- More research is needed to clarify the relationship between estrogen-based contraception and vitamin D levels, as this study only involved African-American women; however, the same association has been observed in other populations.
- To ensure adequate vitamin D levels while trying to conceive and during pregnancy, women planning to stop using birth control are advised to take necessary steps, as further investigation into this relationship continues.
