Evidence check: LCT in the context of Fruchtbarkeit

The evidence for a direct link between the LCT genotype (lactase persistence/non-persistence) and fertility is weak and indirect. LCT determines adult lactose digestion capacity. Lactose intolerance may cause gastrointestinal discomfort, potentially impairing absorption of calcium and vitamin D—both relevant for reproductive health. Some observational studies suggest a possible association between dairy intake and ovulatory fertility, but they rarely genotype LCT. The data are inconsistent: adequate calcium may support oocyte quality, yet no randomized trials directly connect LCT variants to fertility outcomes. Effects are confounded by vitamin D status, gut microbiome, and inflammation. Consumer DNA tests that promote LCT in a fertility context often overstate the evidence. Conclusion: LCT is not an established fertility marker; however, personalized dietary advice for lactose intolerance can help prevent nutrient deficiencies.