Impact of bariatric surgery on vitamin D metabolism and micronutrient deficiencies in severe obesity

• Vitamin D deficiency is common after bariatric surgery, requiring continued monitoring despite weight loss. • 25(OH)D, PTH, and calcium were tracked; PTH >70 pg/mL before surgery linked to lower weight loss after 6 months. • SG preserved acid production and reduced deficiencies in calcium and vitamin D compared to RYGB technique. • After surgery, patients had lower BMI and needed fewer meds, showing improvements in metabolic health. • Monitoring bone health pre- and post-op helps manage hyperparathyroidism and improves long-term results. This study aimed to investigate the impact of bariatric surgery on vitamin D metabolism and associated micronutrient deficiencies in individuals with obesity, emphasizing the prevalence of vitamin D deficiency in patients with severe obesity—a persistent concern after significant weight loss. A comprehensive analysis of serum levels of 25(OH)D, parathyroid hormone (PTH), and calcium was conducted in patients with obesity before and after bariatric surgery, with a six-month follow-up. Medication usage was examined, and outcomes between different surgical techniques were compared. Notable metabolic improvements, linked to reduced BMI and diminished medication reliance post-surgery, were observed. Sleeve gastrectomy (SG) demonstrated potential advantages in preventing micronutrient deficiencies. Many patients had preoperative vitamin D deficiency and elevated PTH levels. Correlation analysis revealed that among those with preoperative PTH levels exceeding 70 pg/mL, higher PTH levels were associated with lower weight loss after six months. No significant correlation was found for vitamin D. This study underscores the importance of critically assessing bone health in bariatric surgery candidates, emphasizing the need for meticulous preoperative evaluation and postoperative monitoring, particularly in cases of secondary hyperparathyroidism. These considerations are pivotal for optimizing the long-term well-being of bariatric surgery patients.