A varied and balanced diet is usually adequate to meet the energy, protein, vitamin, and mineral requirements of adults and the elderly. However, some high-risk groups may require supplementation or special dietary recommendations. Some examples are persons on a weight-loss diet, alcoholics, premenopausal women, women taking oral contraceptives, postmenopausal women not taking estrogen, and patients with diminished immunity or cancer. An understanding of the nutritional needs of adult and elderly patients is vital if the primary care physician is to answer their questions and help them maintain good health through dietary adjustment or supplementation.