Vitamin D signalling in adipose tissue

Abstract

Vitamin D deficiency and the rapid increase in the prevalence of obesity are both considered important public health issues. The classical role of vitamin D is in Ca homoeostasis and bone metabolism. Growing evidence suggests that the vitamin D system has a range of physiological functions, with vitamin D deficiency contributing to the pathogenesis of several major diseases, including obesity and the metabolic syndrome. Clinical studies have shown that obese individuals tend to have a low vitamin D status, which may link to the dysregulation of white adipose tissue. Recent studies suggest that adipose tissue may be a direct target of vitamin D. The expression of both the vitamin D receptor and 25-hydroxyvitamin D 1a-hydroxylase (CYP27B1) genes has been shown in murine and human adipocytes. There is evidence that vitamin D affects body fat mass by inhibiting adipogenic transcription factors and lipid accumulation during adipocyte differentiation. Some recent studies demonstrate that vitamin D metabolites also influence adipokine production and the inflammatory response in adipose tissue. Therefore, vitamin D deficiency may compromise the normal metabolic functioning of adipose tissue. Given the importance of the tissue in energy balance, lipid metabolism and inflammation in obesity, understanding the mechanisms of vitamin D action in adipocytes may have a significant impact on the maintenance of metabolic health. In the present review, we focus on the signalling role of vitamin D in adipocytes, particularly the potential mechanisms through which vitamin D may influence adipose tissue development and function. The vitamin D endocrine system has been linked historically to the aetiology of rickets (1) . Growing evidence suggests that in addition to maintaining Ca homoeostasis and skeletal health (2,3) , vitamin D has pleiotropic actions that can affect multiple organs and metabolic processes, including in the cardiovascular, renal and immune systems (4 -7) . It has been argued that vitamin D deficiency as a global health issue may contribute to the pathogenesis of a number of disorders, including obesity, the metabolic syndrome and type 2 diabetes (8 -11) . Clinical and epidemiological studies show that obese individuals tend to have low vitamin D status (12 -17) .Although vitamin D bioavailability could be reduced in obesity due to increased sequestration by white adipose tissue (13,18) , the mechanisms underlying the inverse relationship between adiposity and vitamin D deficiency are largely unknown. Interestingly, recent studies suggest that (white) adipose tissue could be a direct target of vitamin D, and that the hormone may modulate adipose tissue formation and function (19 -23) . Given the multiplicity of functions of white adipose tissue, and the link between dysfunction of the tissue and the pathogenesis of obesity and its co-morbidities, clarifying the role of vitamin D in adipose tissue may lead to public health benefits.In the present article, we discuss recent advances in our understandin...

Therapeutic impact of cholecalciferol in patients with psychiatric disorders receiving olanzapine

“…However, this finding is different from the results of the study by Mai et al (13). Furthermore, the study of Ding et al revealed that vitamin D3 is effective in metabolism and obesity through controlling adipose tissue, while people with vitamin D3 deficiency are more obese (14). In our study, the difference in waist-hip ratio was statistically significant in intervention group (P < 0.001), but there was no statistically significant difference in group receiving placebo (P = 0.56).…”

“…There are some evidences on the effects of vitamin D3 on body fat, through inhibiting the transcription of lipid cells and regulating fat during the differentiation of fat cells. The study by Ding et al showed vitamin D metabolites also affect adiponectin products and inflammatory responses in adipose tissue (14). Olanzapine is effective in treating all psychiatric disorders.…”

Role of Vitamin D in Atherosclerosis

“…Adipocytes also express the CYP27B1 (1a-hydroxylase) gene. 104 Vitamin D directly activated the transcription factor peroxisome proliferatoractivated receptor-γ, which is implicated in the regulation of fatty acid metabolism in muscle and adipose tissue. …”

Transgenerational Effects on the Liver and Pancreas Resulting from Maternal Vitamin D Restriction in Mice

“…Vitamin D inhibits the differentiation of adipocytes and may be involved in adipocytes apoptosis (5,6). Specifically, vitamin D may affect the intracellular calcium signaling pathways associated with apoptosis in immature and mature adipocytes.…”