Ministrini S, Ricci MA, Daviddi G, et al. - As obesity is identified as a risk factor for vitamin D deficiency and hyperparathyroidism, researchers here sought the determinants of hyperparathyroidism beyond vitamin D deficiency in a cohort of 160 patients with severe obesity who were undergoing laparoscopic sleeve gastrectomy (LSG). Further, they investigated if individual health is negatively influenced by hyperparathyroidism and if the levels of intact parathyroid hormone (iPTH) and 25(OH) vitamin D (25(OH)D) are negatively affected by LSG. In this cohort, vitamin D deficiency was identified in 97% of individuals, and 72% of them had hyperparathyroidism. After correcting for possible confounders, iPTH levels were identified to be correlated with carotid intima-media thickness, as well as with the HOMA index. After the LSG, a significant increase in 25(OH)D levels, while a significant reduction in iPTH levels was observed. They observed a significant correlation of the reduction of iPTH with the reduction of BMI, diastolic blood pressure, and leptin, which was the independent predictor of iPTH reduction. These findings suggest no sole determinative value of vitamin D deficiency for hyperparathyroidism in severe obesity as there appeared a possible role of both visceral fat deposition and leptin. In contrast to previous studies, this work identified obesity-related hyperparathyroidism to be correlated with insulin resistance and atherosclerosis. Finally, LSG intervention led to no negative impact on vitamin D status and resulted in improvement in hyperparathyroidism.