Original article
Prevalence of vitamin D depletion among morbidly obese patients seeking gastric bypass surgery

Presented as an oral presentation at the 22nd Annual Meeting of the American Society for Bariatric Surgery, Orlando, Florida, June 26–July 1, 2005.
https://doi.org/10.1016/j.soard.2005.12.001Get rights and content

Abstract

Background

Abnormalities in calcium and vitamin D metabolism have been reported after bariatric surgery. The purpose of this study was to evaluate vitamin D nutritional status among morbidly obese patients before gastric bypass surgery.

Methods

We prospectively studied 279 morbidly obese patients seeking gastric bypass surgery for vitamin D nutritional status as assessed by serum 25-hydroxyvitamin D level. In addition, serum samples were analyzed for calcium, alkaline phosphatase (AP), intact parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D.

Results

Mean patient age was 43 ± 9 years; 87% of the study patients were women, and 72% were white. Serum calcium and AP levels were normal in 88% and 89% of the patients, respectively. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level ≤ 20 ng/mL, was found in 166 patients (60%). An elevated PTH level was found in 48% of the patients. A significant inverse correlation was found between serum 25-hydroxyvitamin D level and both body mass index (r = .15; P = .012) and serum PTH level (r = .45; P < .001). Vitamin D depletion was significantly more prevalent in the African-American patients than in the white patients (91% vs 48%; P < .001).

Conclusions

Before gastric bypass surgery, a majority of morbidly obese patients have vitamin D depletion and secondary hyperparathyroidism. Studies evaluating the effects of gastric bypass on vitamin D metabolism must consider preoperative vitamin D nutritional status. © 2006 American Society for Bariatric Surgery

Section snippets

Methods

We prospectively collected preoperative data between February 2004 and April 2005 on 301 patients presenting to our Bariatric Surgery Center who we identified as candidates for GBP. Of these 301 patients, 22 had creatinine values above the normal range or abnormal liver function tests and were eliminated from the statistical analysis, leaving a total of 279 patients. Information collected included age, sex, race, and body mass index (BMI).

These morbidly obese surgical candidates were sent for

Results

Mean patient age was 43 ± 9 years (range, 20 to 67 years). Of the total group of 279 patients, 242 (87%) were women, 201 (72%) were white, 69 (25%) were African-American, and 9 (3%) were of another race. The mean BMI was 48 ± 6 kg/m2 (range, 36 to 70 kg/m2). The mean serum PTH level was 59 ± 38 pg/mL, mean 25(OH)D level was 19.6 ± 9 ng/mL, and mean 1,25(OH)2D level was 40.6 ± 13 pg/mL. Serum-corrected calcium (Cac) was normal in 88% of the patients; hypocalcemia was noted in 0.7%, and

Discussion

In this study we found a very high prevalence (60%) of vitamin D depletion in our preoperative morbidly obese patients. Certain factors are associated with a higher prevalence of vitamin D depletion, including increasing age, female sex, African-American race, and residence in a northern latitude [21]. In the present study, a significant difference in serum 25(OH)D level was not correlated with age or sex; however, elderly persons have been shown to have a reduced capacity for cutaneous

References (30)

  • P.S. Coates et al.

    Gastric bypass surgery for morbid obesity leads to an increase in bone turnover and a decrease in bone mass

    J Clin Endocrinol Metab

    (2004)
  • L.R. Goode et al.

    Bone and gastric bypass surgeryeffects of dietary calcium and vitamin D

    Obes Res

    (2004)
  • F. Diniz Mde et al.

    Elevated serum parathormone after Roux-en-Y gastric bypass

    Obes Surg

    (2004)
  • M.T. Ott et al.

    Biochemical evidence of metabolic bone disease in women following Roux-en-Y gastric bypass for morbid obesity

    Obes Surg

    (1992)
  • W.S. Goldner et al.

    Severe metabolic bone disease as a long-term complication of obesity surgery

    Obes Surg

    (2002)

    • Cited by (0)

    View full text
    Copyright © 2006 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.