Like calcium, Vitamin D is necessary for strong teeth and bones. Since fewer Americans are drinking Vitamin D-fortified, many Americans are experiencing a deficiency. Vitamin D is obtained through foods as well and through exposure to sunlight. Because of the concern of skin cancer, many have decreased their exposure to the sun. A deficiency in Vitamin D is a significant problem for post-menopausal women. Because calcium supplementation cannot reverse osteoporosis alone, Vitamin D is required to boost its absorption rate. Together, they may reverse or prevent osteoporosis if taken regularly before menopause. Low levels of Vitamin D may result in high blood pressure and may also cause calcium buildup in the arteries, which may result in a heart attack or stroke. Vitamin D deficiency has also been associated with obesity. Vitabase Vitamin D contains a more absorbable form of Vitamin D, cholecalciferol.