Vitamin D deficiency and hyperparathyroidism with severe bone disease

Abstract Circulating 25‐hydroxycholecalciferol (25OHD3) levels are low in Saudi Arabia due to a lack of sunlight exposure and a low dietary intake of vitamin D (vit D). Recent studies in animals and man indicate that the half‐life of 25OHD3 is reduced in states of hyperparathyroidism. We, therefore, reviewed the charts of 43 patients with primary hyperparathyroidism (HPT) to establish whether there was coexisting vit D deficiency and osteomalacia. In the 22 patients studied, 25OHD3 levels were below normal in 14 and in the low normal range in 7, and the 1,25‐dihydroxycholecalciferol [1,25(OH)2D3] levels were inappropriately low in 8 of the 9 studied. Three of the 13 patients with classical “parathyroid” bone disease had evidence of osteomalacia with Looser's nodes or rickets. We conclude that patients with primary HPT are likely to develop vit D deficiency in countries in which 25OHD3, stores are low. In selected cases, preoperative treatment with vit D might diminish subsequent bone hunger.