Possible connection between vitamin D and contraception methods discovered
Revised Article:
Estrogen-based birth control and vitamin D levels
Here's a fascinating finding from some researchers — women taking estrogen-based birth control pills possess higher amounts of circulating vitamin D. Conversely, those who stop using these contraceptives can experience a significant drop in their vitamin D levels.
So, what's the deal with vitamin D, and why does it matter?
Primarily, vitamin D is responsible for maintaining the right calcium and phosphorus levels in your bloodstream. It also plays a crucial role in absorbing calcium, an essential component in building bones. Interestingly, foods like fish and eggs are rich in vitamin D. However, around 90 percent of this vital nutrient is produced naturally in your skin through a chemical reaction following sun exposure.
Deficiency in vitamin D can lead to health issues like rickets and osteomalacia (softening of the bones). Since vitamin D is crucial during the development of bones, it's especially important during pregnancy.
A researcher from the National Institutes of Health's National Institute of Environmental Health Sciences named Dr. Quaker E. Harmon, took an interest in exploring any potential links between vitamin D levels and oral contraceptives.
Vitamin D and contraception
The team analyzed data from the Study of Environment, Lifestyle, and Fibroids (SELF), an investigation into reproductive health. Roughly 1,700 African-American women aged between 23 and 34 living in and around Detroit, MI were involved in the study. The project asked women about their contraceptive use, spending time outdoors, and any taken vitamin D supplements.
Blood samples were collected from 1,662 women to determine their levels of 25-hydroxy vitamin D, the most common circulating form of vitamin D.
During pregnancy, women produce higher levels of the active form of vitamin D to aid in the growth of the fetal skeleton. With this, pregnant women are at an increased risk of vitamin D deficiency, leading to bone problems.
"Our study found that women using contraception containing estrogen tended to have higher vitamin D levels than other women," Dr. Harmon shared. After accounting for factors that might confuse the results, such as seasonal light exposure, the effect remained significant.
"We couldn't 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 drop when women cease using contraception."
Adjustments for confounding variables revealed the use of contraceptive pills, patches, or rings containing estrogen was associated with a 20 percent increase in 25-hydroxy vitamin D levels. At the same time, current users of birth control had higher levels of vitamin D, while past users displayed average vitamin D levels.
This study, recently published in the Journal of Clinical Endocrinology & Metabolism, hints that as a woman begins trying to become pregnant, she may be at risk of vitamin D deficiency. Dr. Harmon encourages women who are planning to stop using birth control to ensure their vitamin D levels are adequate while trying to conceive and during pregnancy.
When asked why estrogen-based contraception might affect vitamin D levels, Dr. Harmon noted that the rise in DBP may be responsible.
The research looked solely at African-American women. Dr. Harmon mentioned that the association observed in this study is not related to race, as similar findings have been observed in other populations.
Dr. Harmon is continuing to research this group of women to further investigate the relationship and is also working on another group of participants to examine how vitamin D varies across the menstrual cycle.
While the mechanism remains unclear, it's suggested that estrogen interacts with vitamin D receptors and enzymes involved in vitamin D metabolism, leading to a rise in measured total vitamin D levels.
Notes:
- Enhanced vitamin D binding protein: Estrogen increases the synthesis of vitamin D binding protein (DBP) in the liver, causing higher total circulating levels of 25-hydroxyvitamin D (25OHD) and raised measured vitamin D levels.
- Estrogen's influence on cytochrome P450 enzymes: Vitamin D metabolism involves enzymes that catalyze the activation and breakdown of vitamin D metabolites. Estrogen can alter the expression and activity of these enzymes, potentially leading to a shift in the vitamin D metabolism equilibrium.
- Hormonal regulation of vitamin D in reproductive tissues: Vitamin D receptors and metabolism in ovarian and uterine tissues are influenced by estrogen. Vitamin D interacts with estrogen pathways to modulate ovarian steroidogenesis and follicle development, leading to a positive feedback loop that contributes to increased vitamin D levels.
- The increased synthesis of vitamin D binding protein (DBP) in the liver, due to estrogen, causes higher total circulating levels of 25-hydroxyvitamin D (25OHD) and raised measured vitamin D levels in women taking estrogen-based contraceptives.
- In those who cease using estrogen-based contraceptives, a significant drop in vitamin D levels can occur, as suggested by the study involving 1,662 women published in the Journal of Clinical Endocrinology & Metabolism.
- Contraceptives containing estrogen can boost vitamin D levels, with current users displaying higher levels of vitamin D, according to the analysis of data from the Study of Environment, Lifestyle, and Fibroids (SELF).
- As a woman transitions towards pregnancy, she may be at risk of vitamin D deficiency, given the increased risk during pregnancy and the potential drop in vitamin D levels after stopping estrogen-based contraceptives.
- Science continues to unravel the relationship between vitamin D and estrogen-based contraception, with Dr. Harmon exploring potential links and the impact on nutrient metabolism in reproductive tissues.
- Nutrition and health-and-wellness experts emphasize the importance of adequate vitamin D levels, especially for women, to maintain overall health, women's vitamins, and multi-vitamins can serve as a valuable supplement for ensuring the intake of essential nutrients, including vitamin D to support women's health and nutrition.
