TY - JOUR
TI - Vitamin D and Obesity: Current Evidence and Controversies
AU - Karampela, I.
AU - Sakelliou, A.
AU - Vallianou, N.
AU - Christodoulatos, G.-S.
AU - Magkos, F.
AU - Dalamaga, M.
JO - Current Obesity Reports
PY - 2021
VL - 10
TODO - 2
SP - 162-180
PB - Springer-Verlag
SN - 2162-4968
TODO - 10.1007/s13679-021-00433-1
TODO - 25 hydroxyvitamin D;  bisphosphonic acid derivative;  calcitriol;  calcium;  corticosteroid;  estradiol;  fatty acid synthase;  glutathione;  heparin;  ketoconazole;  leptin;  osteocalcin;  parathyroid hormone;  prolactin;  prostaglandin;  sunscreen;  testosterone;  thiazide diuretic agent;  vitamin D;  vitamin D receptor;  vitamin D, adipose tissue;  bariatric surgery;  body composition;  body mass;  body weight;  body weight loss;  bone density;  caloric restriction;  cardiometabolic risk;  chemiluminescence immunoassay;  chemoluminescence;  enzyme linked immunosorbent assay;  fat mass;  food intake;  gastric banding;  gene expression;  high performance liquid chromatography;  human;  hypercalcemia;  hyperparathyroidism;  hyperthyroidism;  kidney disease;  lipid storage;  non insulin dependent diabetes mellitus;  nonhuman;  obesity;  ovary polycystic disease;  physical activity;  protein expression;  radioimmunoassay;  randomized controlled trial(topic);  Review;  seasonal variation;  sleeve gastrectomy;  upregulation;  vitamin D deficiency;  vitamin D metabolism;  waist circumference;  waist hip ratio;  dietary supplement;  drug effect;  factual database;  metabolism;  obesity;  vitamin D deficiency, Adipose Tissue;  Adiposity;  Bariatric Surgery;  Body Weight;  Databases, Factual;  Dietary Supplements;  Humans;  Obesity;  Vitamin D;  Vitamin D Deficiency;  Weight Loss
TODO - Purpose of Review: Evidence from observational studies suggests that obesity is associated with low vitamin D. As both obesity and hypovitaminosis D present an alarmingly increased prevalence worldwide, there is an intense research interest to clarify all aspects of this association. This review summarizes current evidence from meta-analyses investigating vitamin D status in obesity, including the effects of weight loss and bariatric surgery on vitamin D status and the outcomes of vitamin D supplementation on body weight. We also discuss potential pathophysiologic mechanisms and important controversies. Recent Findings: Data from meta-analyses consistently support an inverse association of vitamin D levels with body weight. However, the impact of weight loss on improving vitamin D status is small, while studies on the supplementation with vitamin D after bariatric surgery have shown conflicting results regarding vitamin D status. Moreover, interventional studies do not support a beneficial effect of vitamin D supplementation on body weight. These findings warrant a cautious interpretation due to important methodological limitations and confounding factors, such as high heterogeneity of studies, variable methods of determination of vitamin D and definition of deficiency/insufficiency, use of various adiposity measures and definitions of obesity, and inadequate adjustment for confounding variables influencing vitamin D levels. The underlying pathogenetic mechanisms associating low vitamin D in obesity include volumetric dilution, sequestration into adipose tissue, limited sunlight exposure, and decreased vitamin D synthesis in the adipose tissue and liver. Experimental studies have demonstrated that low vitamin D may be implicated in adipose tissue differentiation and growth leading to obesity either by regulation of gene expression or through modulation of parathyroid hormone, calcium, and leptin. Summary: Obesity is associated with low vitamin D status but weight loss has little effect on improving this; vitamin D supplementation is also not associated with weight loss. Evidence regarding vitamin D status after bariatric surgery is contradicting. The link between vitamin D and obesity remains controversial due to important limitations and confounding of studies. More research is needed to clarify the complex interplay between vitamin D and adiposity. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
ER -