Preoperative micronutrient status in morbidly obese patients before undergoing bariatric surgery: results of a cross-sectional study

Surg Obes Relat Dis. 2015 Sep-Oct;11(5):1157-63. doi: 10.1016/j.soard.2015.03.018. Epub 2015 Apr 2.


Background: Reliable information on micronutrient status before bariatric surgery is needed to optimize preoperative nutritional status and postoperative nutritional therapy.

Objective: To investigate the pro-/vitamin and mineral status and its association with nutrient intake in morbidly obese patients seeking bariatric surgery

Setting: Klinikum Vest, Recklinghausen, Germany.

Methods: The cross-sectional study investigated retinol, ascorbic acid, tocopherol, and β-carotene (high-pressure liquid chromatography), 25-hydroxycholecalciferol (enzyme-linked immunosorbent assay), and calcium, phosphate, and magnesium (photometry) in serum/plasma in 43 patients (body mass index: 52.6±10.5 kg/m(2)) before sleeve gastrectomy. Albumin, parathyroid hormone, and alkaline phosphatase were analyzed. Data were compared with accepted cutoff values. Dietary intake was estimated by 3-day food records, and nutrient intake was compared with recommended values.

Results: One third of participants had ascorbic acid concentrations<28 nmol/L. All patients had β-carotene levels≤.9 µmol/L, although retinol was below the cutoff value (<.7 µmol/L) in only 5%. Tocopherol/cholesterol-ratio was always>2.8 µmol/mmol. Of the patients, 84% had 25-hydroxycholecalciferol levels below 50 nmol/L. Parathyroid hormone was elevated in 23% (>6.5 pmol/L). Calcium, magnesium, and alkaline phosphatase were always, and phosphate was mostly (98%) above cutoff values. Intake of retinol (23%), ascorbic acid (55.8%), vitamin D (90.7%), tocopherol (48.8%), and β-carotene (<2.0 mg/d; 37.2%) were often below recommendations. Correlations between serum/plasma concentrations and nutritional intake and associations between low concentrations and inadequate intake were not observed.

Conclusions: Many morbidly obese patients in Germany suffer from deficiencies in multiple micronutrients, particularly vitamin D, ascorbic acid, and β-carotene before sleeve gastrectomy. Measurement of preoperative micronutrient status will help supplement patients before, and optimize nutritional therapy after, surgery.

Keywords: Bariatric surgery; Dietary intake; Micronutrients; Nutritional deficiencies; Nutritional recommendations; Obesity; Preoperative nutritional assessment.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bariatric Surgery / adverse effects
  • Bariatric Surgery / methods*
  • Body Mass Index
  • Chromatography, High Pressure Liquid
  • Cross-Sectional Studies
  • Deficiency Diseases / diagnosis*
  • Deficiency Diseases / epidemiology
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Follow-Up Studies
  • Germany
  • Humans
  • Male
  • Micronutrients / blood*
  • Micronutrients / deficiency
  • Middle Aged
  • Nutrition Assessment*
  • Nutritional Status
  • Obesity, Morbid / blood*
  • Obesity, Morbid / epidemiology
  • Obesity, Morbid / surgery*
  • Postoperative Care / methods
  • Preoperative Care / methods
  • Risk Assessment
  • Treatment Outcome


  • Micronutrients