Vitamin D deficiency is commonly associated with which form of hyperparathyroidism?

Vitamin D deficiency is commonly associated with which form of hyperparathyroidism?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Hypoparathyroidism

Answer: (B)

When vitamin D is deficient, calcium is not absorbed as well from the gut, which can lower serum calcium. In response, the parathyroid glands ramp up parathyroid hormone to try to lift calcium levels. This increased PTH in the setting of low or normal calcium is secondary hyperparathyroidism. It differs from primary hyperparathyroidism, where the gland itself is overactive and calcium is high due to gland pathology; and from tertiary hyperparathyroidism, which develops after long-standing secondary hyperparathyroidism when the glands become autonomous. Hypoparathyroidism involves low PTH regardless of vitamin D status. So vitamin D deficiency most commonly points to secondary hyperparathyroidism.

When vitamin D is deficient, calcium is not absorbed as well from the gut, which can lower serum calcium. In response, the parathyroid glands ramp up parathyroid hormone to try to lift calcium levels. This increased PTH in the setting of low or normal calcium is secondary hyperparathyroidism. It differs from primary hyperparathyroidism, where the gland itself is overactive and calcium is high due to gland pathology; and from tertiary hyperparathyroidism, which develops after long-standing secondary hyperparathyroidism when the glands become autonomous. Hypoparathyroidism involves low PTH regardless of vitamin D status. So vitamin D deficiency most commonly points to secondary hyperparathyroidism.