Women who stop taking birth control risk a vitamin D deficiency, according to a new study published in the Journal of Clinical Endocrinology & Metabolism.
Researchers arrived at their conclusion after analyzing data and blood samples from young African-Americans participating in the Study of Environment, Lifestyle & Fibroids (SELF) in Detroit. Women answered questions about their birth control use, how much time they spent outdoors, and if they took any vitamin D supplements. Once the data was adjusted for sunlight exposure — a primary source of D — researchers found that women taking birth control pills, patches, and rings containing estrogen had 20 percent higher levels of 25-hydroxy vitamin D in their blood. This is what the kidney changes into the active form of the vitamin, which humans need for a strong immune system and bones.
