Vitamin D deficiency is a major worldwide public health problem affecting people of all ages, from infants to the elderly. Of particular concern is the high incidence of vitamin D deficiency in women during pregnancy and lactation, leading to the exposure of the growing fetus/infant to inadequate levels of vitamin D, which is essential for normal development. Vitamin D deficiency in adulthood is linked to the etiology of hypertension and to a multitude of adverse cardiovascular outcomes. It is now well-established that the antecedents of cardiovascular disease can originate very early in life. The purpose of this review is to highlight how maternal vitamin D deficiency, and its effects in upregulating the fetal renin-angiotensin system and altering cardiomyocyte growth in the fetal heart, has the potential to program long-term vulnerability to cardiovascular disease.