NEW YORK (Reuters Health) - Women with low vitamin D levels are at significantly increased risk of suffering a miscarriage, researchers in the U.K. found in a systematic review and meta-analysis.
"Vitamin D is safe and low cost, so from a public health approach supplements are a great recommendation. Unfortunately, we know that in the UK the uptake of women and pregnant people taking antenatal vitamin supplements remains low at around 20%," Dr. Jennifer Tamblyn of the University of Birmingham said in a news release.
"Vitamin D has only really been known for its role in late pregnancy complications, but our review supports another important role for it too, which could help encourage women about the benefits of taking supplements early," Dr. Tamblyn said.
The analysis included 10 studies - four randomized controlled trials and six observational studies - with a total of 7,663 women.
Women who were vitamin D deficient (<50 nmol/L) had nearly a two-fold increased risk of miscarriage compared with peers who were vitamin D replete (>75 nmol/L; odds ratio, 1.94; 95% CI, 1.25 to 3.02), Dr. Tamblyn and colleagues report in Fertility and Sterility.
A combined analysis comparing vitamin D-deficient or vitamin D-insufficient (50 to 75 nmol/ L) women with vitamin D-replete women similarly found an increased risk of miscarriage (OR, 1.60; 95% CI, 1.11 to 2.30).
Four randomized controlled trials assessed the effect of vitamin D treatment on miscarriage, but "study heterogeneity, data quality, and reporting bias precluded direct comparison and meta-analysis," the study team notes.
The overall quality of the studies included was "low" or "very low" and there was inadequate evidence to accurately assess whether vitamin D treatment reduces the risk of miscarriage.
"New evidence-based interventions are required for women at risk of miscarriage. Vitamin D deficiency is highly prevalent worldwide with pregnant women at particular risk," the researchers write.
"Although traditionally associated with maternal and newborn bone disease, there is now clear recognition of wider detrimental effects, including preterm birth and preeclampsia. Given its excellent safety profile and low cost, even a small effect of vitamin D would be useful when considering a public health approach," they add.
SOURCE: https://bit.ly/3970hPe Fertility and Sterility, online June 9, 2022.
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