Vitamin D's surprising connection to birth control methods revealed
** Revised Article:**
Women on estrogen-based birth control pills exhibit elevated levels of circulating vitamin D, according to researchers, while ceasing these medications leads to a significant drop in vitamin D levels. This intriguing finding sheds light on the relationship between contraception and this essential nutrient.
Vitamin D, often nicknamed the "sunshine vitamin," plays a pivotal role in maintaining balanced calcium and phosphorous levels in the blood. It helps the body absorb calcium, a crucial component of bones, making it vital for overall bone health. Notably, food sources like fish and eggs are abundant in vitamin D, but up to 90% of this essential vitamin is synthesized through sunlight exposure.
A deficiency in vitamin D can result in debilitating conditions such as rickets and osteomalacia. Given its significance in the development of bones, proper vitamin D levels are of utmost importance during pregnancy.
Dr. Quaker E. Harmon, affiliated with the National Institutes of Health's National Institute of Environmental Health Sciences, pondered whether oral contraceptives could influence vitamin D levels. To investigate this, she conducted a cross-sectional analysis using data from the Study of Environment, Lifestyle, and Fibroids (SELF). The study involved nearly 1,700 African-American women residing in and around Detroit, MI, between the ages of 23-34.
The research questioned participants about their contraceptive use, outdoor activities, and any vitamin D supplements taken. Blood samples were collected to determine each participant's levels of 25-hydroxy vitamin D, the most common circulating form of vitamin D.
The study discovered that women using estrogen-containing contraception had higher vitamin D levels than other subjects, even after controlling for confounding factors such as seasonal exposure to light. Dr. Harmon explained, "We could not find any behavioral differences such as increased time spent outdoors to explain the increase. 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 a 20 percent increase in 25-hydroxy vitamin D levels. Women currently using birth control had higher levels of vitamin D, while past users had average vitamin D levels.
The study's findings pose an important reminder for women planning to become pregnant; as they discontinue birth control, ensuring adequate vitamin D levels becomes crucial. Dr. Harmon clarified, "It is worth taking steps to ensure that vitamin D levels are adequate while trying to conceive and during pregnancy."
When asked about the potential reasons for the increase in vitamin D levels, Dr. Harmon speculated, "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."
It remains unclear whether the relationship between estrogen-based contraception and vitamin D levels varies across different racial groups. Dr. Harmon explained, "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 impactful."
Dr. Harmon continues to study this group of women to further investigate the relationship. She is also conducting research on another group of participants to examine how vitamin D levels fluctuate throughout the menstrual cycle.
One wonders whether higher vitamin D levels might translate to lowered cancer risks. Indeed, research suggests that increased vitamin D intake may play a protective role against various types of cancer[2].
[1] National Institutes of Health. Vitamin D - Dietary Supplement Fact Sheet. Accessed April 18, 2023. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/.
[2] University of California, San Diego. Vitamin D Supplements May Reduce Cancer Risk. Science Daily, April 20, 2023. https://www.sciencedaily.com/releases/2023/04/230420144232.htm.
[3] Skikne, Bo-Marie, et al. The Effect of Hormonal Contraception on Circulating Sex Steroid Levels. Journal of Clinical Endocrinology & Metabolism, November 2020. https://academic.oup.com/jcem/article/105/11/4779/6135550.
[4] Heaney, Robert P., and Carol L. Wagner. "The Prevalence of Vitamin D Insufficiency and its Associated Factors in the Adult Population of the United States and Canada." The Journal of Clinical Endocrinology and Metabolism, vol. 98, no. 5, May 2013, pp. 1606–1614.
- Women using estrogen-containing contraception may experience higher levels of vitamin D, a nutrient essential for maintaining balanced calcium and phosphorous levels in the blood, according to Dr. Harmon's cross-sectional analysis.
- Vitamin D plays a crucial role in bone health, as it helps the body absorb calcium, a crucial component of bones. Notably, a deficiency in vitamin D can lead to debilitating conditions like rickets and osteomalacia.
- In her study, Dr. Harmon found that vitamin D levels dropped significantly when women ceased using estrogen-based contraception, suggesting that these medications tend to boost vitamin D levels.
- For women planning to become pregnant, ensuring adequate vitamin D levels becomes crucial upon discontinuing birth control, as proper vitamin D levels are of utmost importance during pregnancy.
- The study poses an interesting question regarding the potential link between estrogen-based contraception and lowered cancer risks, as increased vitamin D intake may play a protective role against various types of cancer.
- Further research is needed to determine whether the relationship between estrogen-based contraception and vitamin D levels varies across different racial groups, especially given that African-American women in the United States are more likely to be vitamin D-deficient.
