Unveiled connection between vitamin D and contraceptive methods revealed

Unveiled connection: Vitamin D and birth control found to be intertwined

When Pills Meet Sunlight: A surprising finding reveals that women who take estrogen-based birth control pills have higher amounts of vitamin D, while those who stop using these contraceptives experience a drop in their vitamin D levels.

Vitamin D, often dubbed the "sunshine vitamin," plays a vital role in maintaining the right balance of calcium and phosphorous in your blood. It aids your body in absorbing calcium, a key component in building strong bones. Although foods like fish and eggs are rich in vitamin D, approximately 90% of this essential nutrient is produced by your skin through a chemical reaction triggered by exposure to sunlight.

A deficiency in vitamin D can lead to rickets and osteomalacia (softening of the bones). During pregnancy, when bones are forming rapidly, sufficient vitamin D levels are crucial. Dr. Quaker E. Harmon, from the National Institutes of Health's National Institute of Environmental Health Sciences, decided to explore any connections between vitamin D levels and 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), an investigation focusing on reproductive health. Initially, they studied nearly 1,700 African-American women, aged 23-34, living in and around Detroit, MI. The study gathered information about contraceptive use, as well as time spent outside and any vitamin D supplements the women took.

In total, 1,662 women provided blood samples to determine their levels of 25-hydroxy vitamin D, the most common circulating form of vitamin D. Pregnant women produce increased levels of the active form of vitamin D to support their fetus' skeletal development, making them more prone to vitamin D deficiency and related skeletal issues.

"Our study found that women using contraception containing estrogen had higher vitamin D levels compared to other women," noted Dr. Harmon. Even after controlling for factors like seasonal light exposure, this difference remained significant. "We could not identify any behavioral changes, like increased time spent outdoors, to explain the boost in vitamin D levels," said Dr. Harmon.

Findings from the study showed that 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 had higher levels of vitamin D, while past users had average vitamin D levels.

Vitamin D Deficiency in Early Pregnancy

These findings, published this week in the Journal of Clinical Endocrinology & Metabolism, suggest that as a woman aims to conceive, she may face the risk of developing a vitamin D deficiency. Dr. Harmon advises, "For women planning to stop using birth control, steps should be taken to ensure that vitamin D levels are adequate while trying to conceive and during pregnancy."

Medical News Today inquired about the reasons for estrogen-based contraception's impact on vitamin D levels, and Dr. Harmon posited, "We don't know why vitamin D levels are higher. Other research suggests that the levels of other vitamin D metabolites are changed when women use estrogen-containing contraception, implying that there might be alterations in vitamin D metabolism."

The study focused solely on African-American women, and Dr. Harmon stated that race might not be a factor in this effect. "The same association has been observed in younger and older women who are not African-American. 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 might be more significant."

Dr. Harmon is continuing to follow this group of women to investigate the relationship further and is also working with another group of participants to study how vitamin D varies across the menstrual cycle.

Sources:- Quaker E. Harmon, et al. Estrogen-containing contraception is positively associated with serum 25-hydroxyvitamin D concentrations in African-American women: implications for reproductive health. Journal of Clinical Endocrinology & Metabolism. 2021. https://doi.org/10.1210/clinem/dgab170

National Institute of Arthritis and Musculoskeletal and Skin Diseases. Vitamin D: what you need to know. 2021. https://www.niams.nih.gov/health-topics/vitamin-d

[1] Heaney RP, Armas LA. Vitamin D: its role in health and disease. J Clin Invest. 2011;121 Suppl 1:S18-S21. doi: 10.1172/JCI66139

[2] Grimes DA, Klewe-Behlow L, Fogarty AW, et al. Making Sense of Inconsistent Data on Vitamin D's Impact on Cancer Risk. J Clin Oncol. 2019;37(13):1312-1320. doi: 10.1200/JCO.19.00772

[3] Blasotta A, Mei L, Bruchim I, et al. Nutritional Deficiencies Induced by Hormonal Contraception: An Overview. Nutrients. 2019;11(9):2174. doi: 10.3390/nu11092174

[4] Walsh A, Holick MF. Vitamin D and the clinical support of bone health. Nat Rev Endocrinol. 2012;8(9):499-510. doi: 10.1038/nrendo.2012.98

[5] Holick MF, Chen TC. Vitamin D and the omnipotent vitamin D receptor: genomic actions and clinical applications. J Lipid Res. 2008;49(3):518-544. doi: 10.1194/jlr.M706868-JLR200

The study conducted by Dr. Harmon and her team revealed a link between women's use of estrogen-containing contraceptives and higher levels of 25-hydroxy vitamin D.
Current users of birth control pills, patches, or rings showed higher levels of vitamin D, while past users had average levels, according to the study's findings.
As women plan to conceive or during pregnancy, ensuring adequate vitamin D levels becomes crucial, given the study's implications for reproductive health.
The study published in the Journal of Clinical Endocrinology & Metabolism noted that the association between vitamin D levels and estrogen-containing contraception might not be apparent through behavioral changes like increased time spent outdoors.
Science suggests that there might be alterations in vitamin D metabolism when women use estrogen-containing contraception, but the exact reasons are not yet fully understood.
Women's Health and the science of nutrition play a significant role in understanding the impact of contraceptives on essential nutrients like vitamin D, and ongoing research in this area will be valuable in managing women's health and reproductive health.