Vitamin D Deficiency: Consequence or Cause of Obesity?

Abstract

Obesity is defined as an excess amount of body fat and represents a significant health problem worldwide. High prevalence of vitamin D (VD) deficiency in obese subjects is a well-documented finding, most probably due to volumetric dilution into the greater volumes of fat, serum, liver, and muscle, even though other mechanisms could not completely be excluded, as they may contribute concurrently. Low VD could not yet be excluded as a cause of obesity, due to its still incompletely explored effects through VD receptors found in adipose tissue (AT). VD deficiency in obese people does not seem to have consequences for bone tissue, but may affect other organs, even though studies have shown inconsistent results and VD supplementation has not yet been clearly shown to benefit the dysmetabolic state. Hence, more studies are needed to determine the actual role of VD deficiency in development of those disorders. Thus, targeting lifestyle through healthy diet and exercise should be the first treatment option that will affect both obesity-related dysmetabolic state and vitamin D deficiency, killing two birds with one stone. However, VD supplementation remains a treatment option in individuals with residual VD deficiency after weight loss.

Efficiency of Vitamin D Supplementation in Healthy Adults is Associated with Body Mass Index and Baseline Serum 25-Hydroxyvitamin D Level

“…Jansen et al reported that BMI should be considered for better estimation of the loading dose of cholecalciferol needed to treat vitamin D deficiency [ 37 ], but they noted that this does not exclude large interindividual variation in dose response. It is well established that obese people have higher risk for vitamin D deficiency [ 38 , 39 ]; Drincic et al reported that most parsimonious explanations for this is simple dilution of 35-OH-vitD in the larger fat and tissue mass [ 40 ]. They also investigated response to graded cholecalciferol supplementation among obese adults [ 41 ], showing that, in obese patients, the dose of vitamin D should be adjusted considering the body size.…”

Prevalence of vitamin D status and its association with overweight or obesity in a population of Colombian children and adolescents

“…Therefore, it is not affected by the climatic seasons. Other mechanisms of association between vitamin D and overweight or obesity are widely described in Vranić et al ., according to the consequence and the cause( 21 ). Among them, ‘ its deficiency has been associated with a large number of disorders such as metabolic syndrome, cancers, and autoimmune, psychiatric, and neurodegenerative diseases, but the causative role of VD deficiency in many of these conditions remains unclear.…”

“…Among them, ‘ its deficiency has been associated with a large number of disorders such as metabolic syndrome, cancers, and autoimmune, psychiatric, and neurodegenerative diseases, but the causative role of VD deficiency in many of these conditions remains unclear. Since VD deficiency is related to visceral adiposity; it could be used as a biomarker of a visceral adiposity-related dysmetabolic state (cardiovascular diseases, type 2 diabetes, dyslipidemia, arterial hypertension) ’( 21 ).…”

Vitamin D Supplementation Improves Adipose Tissue Inflammation and Reduces Hepatic Steatosis in Obese C57BL/6J Mice

“…Nowadays, according to the World Health Organization (WHO), over 1.9 billion adults are overweight and among them 650 million are obese [3]. This pathology is strongly related to metabolic disorders such as arterial hypertension, chronic low-grade inflammation, and insulin resistance that could lead to type 2 diabetes [4,5]. Obesity is also strongly linked to ectopic fat accumulation, particularly in the liver, contributing to an emergence of non-alcoholic fatty liver disease (NAFLD) [6].…”