Vitamin D (vit. D) deficiency is common during pregnancy (Holick, et al., 2011). Supplementation of vit. D has shown to protect against complications and adverse outcomes during pregnancy (De-Regil LM, 2016). A comprehensive literature search and review was conducted to locate articles related to pregnancy outcomes. The literature review found thirteen studies related to vit. D and impact on pregnancy, twenty-five studies examined adverse pregnancy outcomes related to vit. D deficiency and eight studies examined current vit. D intake among pregnant women. Evidence shows a positive association between vit. D deficiency and pregnancy, suggesting that vit. D sources require closer examination and recommendations for pregnant women and women of childbearing age. Evidence shows mixed results with correlation of vit. D deficiency to adverse pregnancy outcomes. Vitamin D supplementation has shown to contribute to total vit. D intakes and shows adequate increases in serum 25-hydroxyvitamin-D (25(OH)D) levels with supplementation.