Hidden connection discovered between vitamin D and contraceptive methods
A study led by Dr. Quaker E. Harmon of the National Institutes of Health's National Institute of Environmental Health Sciences has revealed that women using estrogen-based contraceptives show higher levels of circulating vitamin D. Cessation of these contraceptives, on the other hand, is associated with a significant drop in vitamin D levels.
Vitamin D performs a vital function in maintaining the correct balance of calcium and phosphorus in the blood. It also aids in the absorption of calcium, an essential component of bones. Foods such as fish and eggs, as well as sunlight exposure, are primary sources of vitamin D. However, around 90% of the vitamin is produced in the skin through a chemical reaction following exposure to sunlight.
Deficiency in vitamin D can lead to rickets and osteomalacia (softening of the bones), making it crucial during pregnancy due to its relevance in the formation of bones. The study aimed to investigate any changes in vitamin D levels associated with the use of oral contraceptives.
The researchers conducted a cross-sectional analysis of data from the Study of Environment, Lifestyle, and Fibroids (SELF), involving almost 1,700 African-American women living in and around Detroit, MI, aged 23-34. The project asked women about their contraceptive use and included questions about the amount of time they spent outside and any vitamin D supplements they took. In total, 1,662 women provided blood samples to ascertain levels of the most common circulating form of vitamin D, called 25-hydroxy vitamin D.
The study found that women using contraception containing estrogen tended to have higher vitamin D levels than other women. When controlling for confounding factors such as seasonal exposure to light, the effect remained significant. The researchers could not find any behavioral differences to explain the increase. After adjustments for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with 20 percent higher levels of 25-hydroxy vitamin D.
As women plan to stop using birth control, it is worth taking steps to ensure sufficient vitamin D levels, particularly during pregnancy. The study's findings suggest that contraceptives containing estrogen tend to boost vitamin D levels, and those levels are likely to fall when women cease using contraception.
The current study looked solely at African-American women. The researchers believe that this association is not related to race, as it has been observed in other women regardless of race. In the United States, African-American women are more prone to vitamin D deficiency, making even small increases or decreases in their vitamin D concentrations more important. The study's family is continuing to investigate the relationship further.
While the study did not directly examine racial differences in the effect of estrogen-based contraception on vitamin D levels, it is essential to note that baseline vitamin D status varies significantly across racial groups due to factors like skin pigmentation, sun exposure, and dietary habits. If estrogen-based contraceptives further impact free, active vitamin D or cause deficiencies in specific populations, these groups may be at greater risk of deficiency.
Further research is needed to clarify racial differences in this effect. Overall, estrogen-based contraception can impact vitamin D status, primarily by altering binding proteins and possibly reducing free, active vitamin D. This effect is more pronounced in populations already at risk for deficiency, and while it is likely to occur across different racial groups, the magnitude may vary due to baseline vitamin D status, skin pigmentation, and environmental factors.
- Given the study by Dr. Quaker E. Harmon, it is noteworthy that women using estrogen-based contraceptives have higher levels of circulating vitamin D.
- Vitamin D plays a crucial role in maintaining the balance of calcium and phosphorus in the blood and aiding in the absorption of calcium, an essential component of bones.
- Deficiency in vitamin D can lead to serious health issues like rickets and osteomalacia, making it crucial, especially during pregnancy.
- Aiming to investigate any changes in vitamin D levels associated with the use of oral contraceptives, the study conducted a cross-sectional analysis involving nearly 1,700 African-American women.
- After adjustments for confounding variables, the use of contraceptive pills, patches, or rings containing estrogen was associated with 20 percent higher levels of 25-hydroxy vitamin D.
- Despite the current study focusing on African-American women, the association is not believed to be related to race, and further research is necessary to clarify racial differences in this effect and assess its impact on various populations.
