Resumen: Vitamin D deficiency is common and there exists a huge gap between recommended dietary vitamin D intakes and the poor vitamin D supply in the general population. While vitamin D is important for musculoskeletal health, there are accumulating data suggesting that vitamin D may also be important for fertility, pregnancy outcomes and lactation. Significant changes in vitamin D metabolism during pregnancy such as increased production of the “active vitamin D hormone” calcitriol support the important role of vitamin D in this setting. Observational studies show that vitamin D deficiency is a risk marker for reduced fertility and various adverse pregnancy outcomes and is associated with a low vitamin D content of breast milk. Meta-analyses of randomized controlled trials (RCTs) document that physiological vitamin D supplementation during pregnancy is safe and improves vitamin D and calcium status, thereby protecting skeletal health. Although certain RCTs and/or meta-analyses reported some other beneficial effects, it is still not clear whether vitamin D supplementation improves fertility or decreases the risk of adverse pregnancy outcomes such as low birth weight, pre-eclampsia and neonatal mortality, or reduces wheeze/asthma in the infants. Nevertheless, vitamin D supplementation in pregnant women is frequently required to achieve a sufficient vitamin D status as recommended by nutritional vitamin D guidelines. In this review, we provide an overview of systematic reviews, meta-analyses and large trials reporting clinical data on the role of vitamin D for fertility, pregnancy and lactation. Idioma: Inglés DOI: 10.3390/ijerph15102241 Año: 2018 Publicado en: International Journal of Environmental Research and Public Health 15, 10 (2018), 2241 [19 pp] ISSN: 1661-7827 Factor impacto JCR: 2.468 (2018) Categ. JCR: PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH rank: 38 / 162 = 0.235 (2018) - Q1 - T1 Categ. JCR: ENVIRONMENTAL SCIENCES rank: 112 / 250 = 0.448 (2018) - Q2 - T2 Categ. JCR: PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH rank: 67 / 185 = 0.362 (2018) - Q2 - T2 Factor impacto SCIMAGO: 0.818 - Public Health, Environmental and Occupational Health (Q2) - Health, Toxicology and Mutagenesis (Q2)