Vitamin D deficiency before bariatric surgery: should supplement intake be routinely prescribed?

Before bariatric surgery, we demonstrate a 96% rate of vitamin D deficiency in morbidly obese French patients: should supplement intake be routinely prescribed? We conducted a prospective observational study to demonstrate the prevalence of vitamin D deficiency in morbidly obese patients awaiting bariatric surgery.

Clinical and biological data were collected on 50 successive patients.

Data showed vitamin D deficiency in 96% (25-OH vitamin D = 31 ± 13 nmol/l), with a cut-point of 50 nmol/l. Secondary hyperparathyroidism was found in 44% of patients with hypovitaminosis D (parathyroid hormone (PTH), 59 ± 24 pg/ml). Impaired PTH level concerned 89% of this group, considering the cut-point at 30 pg/ml. No significant correlation appeared between vitamin D and calcium or phosphate levels.

Before surgery, we demonstrated a higher incidence of vitamin D deficiency in morbidly obese French patients as compared to the general population. The incidence was also higher than previous American studies. Screening for hypovitaminosis D may routinely be considered in morbid obesity. Long-term observation is, however, needed to assess the advantages and potential side effects of systematic vitamin D supplements.