Findings from a Danish nationwide cohort study indicate that regular dietary intake with vitamin D substantially improves the odds that a woman diagnosed with infertility would have a live child. Danish researchers have spent a decade investigating the impact that such treatment may have on the possibility that women diagnosed with infertility would give birth to babies.
Records of 16,212 women with a confirmed diagnosis of female infertility were checked between June 1, 1980, and August 31, 1991. Information including the date of each patient’s fertility examination, cause of infertility, and personal identity number were collected from the Danish Infertility Cohort, the National Patient Registry, and the Danish IVF Database.
The Process:
Patients in the research were divided into three groups depending on the date they were diagnosed with primary infertility:
- The vitamin D exposed group, diagnosed from study start to May 31, 1985;
- A “wash-out” period group, diagnosed from June 1, 1985 to August 31, 1986;
- And a vitamin D non-exposed group, diagnosed from September 1, 1986 to August 31, 1991.
Statistical approaches were used to measure the odds ratios for the relationship between the intake to vitamin D and the probability to live birth within a year of infertility diagnosis, and the findings were modified for age at the time of diagnosis.
The Results:
Women diagnosed with infertility during the Vitamin D exposure period had an 87% better likelihood of having a live birth within 12 months of their diagnosis; compared to women diagnosed later during the non-exposed period. Those who were treated during the transient wash-out phase have had a greater (52% higher) possibility of pregnancy relative to unexposed women.
ASRM President-elect Hugh Taylor, MD, said, “This massive, national study indicates that minor changes in vitamin D rates may have appreciable beneficial effects on infertility patients. Vitamin D deficiency is normal where exposure to sunlight is reduced and affects several of our patients. While more studies on vitamin D and human reproductive function are required, we should advise women who are attempting to conceive that vitamin D supplementation may be helpful.”
