Many American women consume diets high in phosphorus and low in calcium. Concern
about this dietary pattern stems from studies that show high phosphorus, low calcium intake
causes secondary hyperparathyroidism and bone loss in several animal models. Recent
studies in young adults have shown that a high phosphorus, moderately low calcium intake
results in mild secondary hyperparathyroidism that persisted over 4 wk. However, plasma
concentrations of the active form of vitamin D did not change in these subjects, despite …