Endocrine Abstracts

Bariatric surgery is a common treatment for morbidly obese patients requiring weight loss and/or metabolic control. Vitamin D (VitD) deficiency and bone loss may occur post-operatively and supplementation with high oral doses of Vitamin D is required. Alternatively, intramuscular depot ergocalciferol (vitamin D2) which slowly releases VitD and overcomes the gastrointestinal tract, could be administrated in such patients.

Aim: To present a case of severe VitD deficiency–osteomalacia after gastric bypass operation for morbid obesity treated with ergocalciferol intramuscularly.

Case report: A 45-year-old woman (BMI 43 kg/m²) was referred to the Endocrinology Department with a diagnosis of secondary hyperparathyroidism due to VitD deficiency. Two weeks earlier, she was admitted to the Department of Internal Medicine for pain at the upper third of left hip and pelvis and long-standing muscle weakness over the previous months. The last month she was immobilized in a wheelchair. Fifteen years ago she underwent roux-en-Y gastric by-pass for treatment of morbid obesity. Since then she was treated with multivitamin supplements (iron, VitB12, Calcium, VitD). In the last three months, after a neurological examination anti-epileptics and analgesics were also initiated. Despite this treatment, she complained for hips’ pain and muscle weakness, which limited her ambulation. During her hospitalization, iron deficiency anaemia (Ht 23%, Hb 8g/dl Ferritine 3 μg/l) vitD deficiency (25OHD 3.7 ng/ml) and secondary hyperparathyroidism (PTH 334 pg/ml, Ca 8.3 mg/dl, Albumin 3 gr/dl, P 1.7 mg/dl, CaUr24h 30 mgr/24 h, PUr24h 200 mgr/24 h) were revealed. The indices of bone turnover (ALP 173IU/L, P1NP 196 ng/ml, βCTX 2.02 ng/ml) were elevated. Radiological evaluation demonstrated insufficiency fractures on the pubic and left femur and reduced lumbar spine (Tscore −2.8) and hip (Tscore −2.9) BMD. Osteomalacia due to vitD deficiency and calcium malabsorption was diagnosed. Calcium citrate 2000 mg daily and im ergocalciferol 600,000 IU every 20 days to correct vitD deficiency were initiated whereas anti-epileptics and analgesics were discontinued. One month after treatment initiation, musculoskeletal pain and weakness had resolved and the patient was mobilized almost completely. Within two months, hyperparathyroidism (PTH 175 pg/ml, Ca 8.7 mg/dl, P 3.5 mg/dl, Albumin 3.3 g/dl, ALP 206 IU/l, P1NP 668 ng/ml, βCTX 4.25 ng/ml) and vitD status (25(OH)D 8.1 ng/ml) had improved.

Conclusion: Regular monitoring and prompt correction of vitD and mineral deficiencies is necessary in patients that underwent bariatric surgery. Intramuscular ergocalciferol administration can improve the clinical and biochemical status and thus is suggested to prevent and/or treat osteomalacia in such patients.