Is Vitamin D deficiency a risk factor for osteonecrosis of the jaw in patients with cancer? A matched case-control study.

A previous case-control histomorphometric study showed higher odds of osteomalacia in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ). Vitamin D deficiency causes osteomalacia and may therefore be involved in the pathogenesis of BRONJ. The present case-control study aimed at testing such hypothesis. BRONJ+ and - patients treated with bisphosphonates were matched by gender (same) and age (within 5 years). Serum 25-hydroxy-vitamin D (25-OH-D), parathyroid hormone, bone alkaline phosphatase, total procollagen type 1 amino-terminal propeptide, carboxy-terminal collagen crosslinks, Dickkopf WNT signaling pathway inhibitor 1 and sclerostin were measured. The main outcome was vitamin D deficiency defined as 25-OH-D < 50 nmol/l. 51 BRONJ+ and 73 BRONJ- patients were studied. The frequency (95%CI) of vitamin D deficiency was 59% (45% to 72%) in BRONJ+ and 62% (48% to 75%) in BRONJ- patients. This amounts to a difference of -3% (-22% to 16%, p = 0.77) for BRONJ+ patients. Serum 25-hydroxy-vitamin D and parathyroid hormone were similar in BRONJ+ and BRONJ- patients. Among the bone metabolism markers, only sclerostin differed between the two groups, being higher in BRONJ+ patients. The present matched case-control study suggests that vitamin D deficiency is not a risk factor for BRONJ.