Unveiled research suggests a possible link between vitamin D levels and the effectiveness of birth control methods.
The Scoop on Estrogen-Based Contraception and Vitamin D Levels
Taking estrogen-based birth control pills isn't just about preventing unwanted pregnancies; it might also mean higher vitamin D levels for women. Researchers have discovered that women on these contraceptives have increased amounts of vitamin D in their circulation, while those who stop taking them face a significant drop in this essential nutrient.
Vitamin D is no stranger to us, as it's crucial for maintaining the correct calcium and phosphorus levels in our bloodstream. It also helps our bodies absorb calcium, a building block for strong bones. Many foods contain this vitamin, with fish and eggs being some of the richest sources, but about 90% of our daily dose comes from exposure to sunlight.
However, a vitamin D deficiency can lead to problems like rickets and osteomalacia (softening of the bones), and it's particularly important during pregnancy because of the formation of the fetal skeleton.
To investigate this interesting finding, Dr. Quaker E. Harmon of the National Institutes of Health's National Institute of Environmental Health Sciences in Research Triangle Park, NC, decided to investigate any changes in vitamin D levels associated with taking oral contraceptives.
The Link Between 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 reproductive health investigation that included nearly 1,700 African-American women residing in and around Detroit, MI, aged 23-34.
The study asked women about their contraceptive use and other factors, such as time spent outside and vitamin D supplements consumed. Close to 1,662 women provided blood samples to determine their levels of the most common circulating form of vitamin D, known as 25-hydroxy vitamin D.
The researchers found that women using contraception containing estrogen tended to have higher vitamin D levels than other women. After making adjustments for factors like seasonal exposure to light, 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."
After making adjustments for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with a 20% increase in 25-hydroxy vitamin D levels. Current users of birth control had higher levels of vitamin D, and past users had average vitamin D levels.
These findings, published in the Journal of Clinical Endocrinology & Metabolism, mean that as a woman starts trying to become pregnant, she runs the risk of becoming deficient in vitamin D.
Dr. Harmon advises women who plan to stop using birth control to take steps to ensure their vitamin D levels are adequate while trying to conceive and during pregnancy.
Research suggests that the increase in vitamin D levels is due to estrogen's influence on vitamin D metabolism and related hormone-binding proteins. Estrogen stimulates the liver to produce more sex hormone-binding globulin (SHBG) and likely increases vitamin D binding protein levels, leading to higher overall vitamin D levels.
Estrogen also affects vitamin D metabolism enzymes, such as CYP24A1, which catabolizes active vitamin D, potentially contributing to higher circulating 25OHD concentrations. Improved vitamin D status may benefit pregnancy outcomes by optimizing calcium homeostasis and absorption.
Women not using estrogen-based contraception may have lower vitamin D levels, increasing the risk of deficiency, which could impair reproductive health and pregnancy outcomes. Ensuring adequate vitamin D intake and monitoring levels is important, especially for women with irregular menstrual cycles or conditions like PCOS, where hormone and vitamin D metabolism can be disrupted.
- Estrogen-based birth control pills might lead to increased vitamin D levels in women, according to a study by Dr. Quaker E. Harmon and her team.
- The higher vitamin D levels in women on these contraceptives could decrease the risk of deficiencies, which can result in problems like rickets and osteomalacia, particularly during pregnancy.
- Dr. Harmon's study, published in the Journal of Clinical Endocrinology & Metabolism, found a 20% increase in 25-hydroxy vitamin D levels associated with the use of contraceptive pills, patches, or rings containing estrogen.
- As a woman starts trying to become pregnant, she might experience a drop in vitamin D levels if she stops using estrogen-based contraception, making it important to ensure adequate vitamin D intake during this period.
- The study suggests that the increase in vitamin D levels is due to estrogen's influence on vitamin D metabolism and related hormone-binding proteins, such as sex hormone-binding globulin (SHBG) and vitamin D binding protein.
- Women not using estrogen-based contraception may have lower vitamin D levels, increasing the risk of deficiency, which could impair reproductive health and pregnancy outcomes, especially for women with irregular menstrual cycles or conditions like PCOS where hormone and vitamin D metabolism can be disrupted.
