PTH and primary hyperparathyroidism: Vitamin D deficiency is common in people with severe and complex obesity19, 29, 30, 32, 34, 38, 40, 42, 43, 44, 45, 46, 47, 48, 50, 58, 61, 62, 63, 64, 65 with reports as high as 99% of participants in one study conducted by Ben‐Porat et al.40A raised albumin‐adjusted serum calcium in the presence of raised parathyroid hormone (PTH) may indicate primary hyperparathyroidism, and so both PTH and calcium should be measured preoperatively.66