Vitamin D Boosts Chances of Having a Child

Adapted from Jensen et al, Exposure to vitamin D fortified margarine in women with fertility problems and chance of live birth: results from a Danish population-based cohort study

Results from a Danish nationwide cohort study suggest that consistent dietary vitamin D supplementation significantly increases the chances a woman diagnosed with infertility will have a live birth.

Vitamin D deficiency is common if exposure to sunlight is limited and it affects many of our patients.

Danish researchers took advantage of a unique time period- five years of a nationwide dietary program to increase vitamin D levels- to examine the effect such supplementation may have on the likelihood that women diagnosed with infertility would deliver a child.

They examined the records of 16,212 women with a primary diagnosis of female infertility.

The first five years of the study’s date range fell within Denmark’s mandatory vitamin D fortification program for margarine with an approximate level of 50 IU per 100 grams of margarine, amounting to 13% of the daily vitamin D intake for adults.

Patients in the study were separated into three groups depending on the date they received their primary infertility diagnosis: the vitamin D exposed group, a “wash-out” period group (14 months after vitamin D fortification of margarine stopped), and a vitamin D non-exposed group. Statistical methods were used to calculate odds ratios for the association between vitamin D exposure and the chance of live birth within a year of infertility diagnosis and the results were adjusted for age at the time of diagnosis.

Women diagnosed with infertility during the vitamin D exposed period had an 87% higher chance of having a live birth in the 12 months following their diagnosis, compared to women diagnosed later, during the non-exposed period. Women diagnosed during the transitional, wash-out period also had an increased (52% higher) chance of live birth compared to unexposed women.

Additional analyses showed that neither seasonal variation (summer versus winter conception) nor a more extended follow-up period affected the association between vitamin D exposure and the chance of live birth.

This large, nationwide study shows that small increases in vitamin D levels can have considerable positive effects on infertility patients.

February 2020