Endocrine Abstracts

Introduction: Vitamin D is a liposoluble molecule which takes part in calcium–phosphorous homeostasis of the human body. Its optimum levels according to SEIOMM range between 30 and 75 ng/ml. Being liposoluble substances they require the presence of biliar salts for their absorption; 80% is absorbed in the yeyune and in a lesser extent in the duodene. The correct concentration of vitamin D is of key significance in obesity, particularly its visceral type. An excessive body weight is thought to represent a significant determinant of a reduced vitamin D concentration in serum. Due to its high metabolic activity, visceral adipose tissue promotes sequestration and alterations in turnover of the vitamin-resembling hormone. Care for elimination of the factors which promote deficiencies is particularly essential in obese persons in whom degree of adiposity correlates with reduced concentrations of this vitamin in blood. Given the importance of this vitamin in the body we have analysed its levels in obese patients which were going to follow a VLCD (600 kcal) before undergoing bariatric surgery. The patients followed a VLCD during 4 weeks before the surgery. The values of vitamin D were analysed at two different moments: before beginning the diet and after the diet, 4 weeks later.

Method: We have designed a prospective observational study; 18 patients were analysed with IMC >35 kg/m² with associated comorbility or IMC >40 kg/m², between 18 and 60 years old, candidate for bariatric surgery with laparoscopic gastric by-pass. Vitamin D concentrations were monitored at two different moments: 1 month before surgery and at the moment of surgery, 4 weeks after the VLCD.

Objective: To establish whether there are statistically significant variations in the values of vitamin D before and after following a VLCD.

Results: We obtain an average level of vitamin 25 (OH) D of 16,31 ng/ml in the analytical evaluation 1 month before surgery and 21,32 ng/ml at the time of the surgery, which takes place at the end of the VLCD. Statistically significant differences are observed between the levels of vitamin 25 (OH) D 1 month before surgery and at the time of the chirurgical act.

Conclusions: According to the results, patients that follow a 4-week VLCD significantly improve the levels of vitamin 25 (OH)D in blood. Those levels do not reach a normal level after the diet, however it is evident the benefit of the recommended process, and it would be interesting to evaluate in the long term if such a tendency remains.