Menopause is the time at which menstruation stops in women. After menopause, women are more susceptible to some diseases, especially osteoporosis and cardiovascular disease. Vitamin D has a protective effect against osteoporosis by facilitating the absorption of calcium and affecting parathyroid hormone. Vitamin D also affects cardiovascular function by lowering the blood pressure, which affects the renin–angiotensin system and alters the low-density lipoprotein receptor activity. This paper discusses supplemental vitamin D in postmenopausal women with osteoporosis and cardiovascular disease.