Vitamin D Deficiency in the Morbidly Obese

Buffington, Cynthia; Walker, B.; Cowan, George S M; Scruggs, David

doi:10.1381/096089293765559142

Cited by 136 publications

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“…4,5,19,[48][49][50][51][52] The high prevalence of low VD levels in obesity is proposed to be due to volumetric dilution in obesity, as the volume of distribution of VD increases with increased body weight. 23 Our study aimed to elucidate whether low plasma 25OHD levels in obesity could be further explained by an altered VD metabolism.…”

Section: Discussionmentioning

confidence: 99%

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

et al. 2012

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OBJECTIVE: Low vitamin D (VD) levels are common in obesity. We hypothesized that this may be due to metabolism of VD in adipose tissue (AT). Thus, we studied (1) whether the VD-metabolizing enzymes were expressed differently in AT of lean and obese individuals and in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and (2) whether their expression was influenced by weight loss. METHODS: Samples of SAT and VAT were analyzed for expression of the vitamin-D-25-hydroxylases CYP2R1, CYP2J2, CYP27A1 and CYP3A4, the 25-vitamin-D-1a-hydroxylase CYP27B1, the catabolic vitamin-D-24-hydroxylase CYP24A1, and the vitamin D receptor, using reverse transcriptase-PCR. Moreover, plasma 25-hydroxy-vitamin D (25OHD) level was measured and related to the expression of these enzymes. Samples of SAT and VAT from 20 lean women and 20 obese women, and samples of SAT from 17 obese subjects before and after a 10% weight loss were analyzed. RESULTS: A plasma 25OHD level o50 nmol l À 1 was highly prevalent in both lean (45%) and obese (90%) women (Po0.01). Plasma 25OHD increased by 27% after weight loss in the obese individuals (Po0.05). Expression levels of the 25-hydroxylase CYP2J2 and the 1a-hydroxylase CYP27B1 were decreased by 71% (Po0.0001) and 49% (Po0.05), respectively, in SAT of the obese. CYP24A1 did not differ between lean and obese women, but the expression was increased by 79% (Po0.05) after weight loss. CONCLUSION: Obesity is characterized by a decreased expression of the 25-hydroxylase CYP2J2 and the 1a-hydroxylase CYP27B1 in SAT, whereas the catabolic CYP24A1 does not differ between lean and obese women. However, the expression of CYP24A1 is increased after weight loss. Accordingly, AT has the capacity to metabolize VD locally, and this can be dynamically altered during obesity and weight loss. INTRODUCTIONLow levels of circulating 25-hydroxy-vitamin D (25OHD) are associated with increased fat mass and body mass index, 1-5 but the underlying mechanism for this association is not fully elucidated. 6 Vitamin D (VD) is stored in adipose tissue (AT), and release of VD from AT is proposed to serve as an endogenous source of VD during the winter, when cutaneous production is low or absent in several parts of the world. 7 As low circulating levels of 25OHD are common in association with the obese state, 8 several studies have examined the effect of weight loss on circulating levels of 25OHD. However, results are inconsistent. After diet-and exercise-induced weight loss, both increased 9-11 and unaltered 12,13 circulating levels of 25OHD have been reported. Likewise, after major weight loss by bariatric surgery, both temporary 14-16 and long-term increases [16][17][18] in circulating levels of 25OHD have been reported, along with reports of no changes one year after surgery. 13,19 Taken together, these findings indicate that body weight is an important factor for circulating 25OHD levels. Several other explanations for the low levels of 25OHD in obesity have been proposed: a decreased exposure to sun light, 20 ...

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Section: Discussionmentioning

confidence: 99%

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

et al. 2012

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“…12,13 The levels of serum 1,25-dihydroxyvitamin D (1,25(OH) 2 D) were elevated, whereas 25-hydroxyvitamin D (25(OH)D) levels were reduced in morbidly obese patients. 12,14,15 In addition, the levels of serum vitamin D metabolites inversely correlate with fat mass 12,16 and body mass index (BMI). 16 Therefore, DBP, playing an important role in the vitamin D endocrine system by binding with 25(OH)D and 1,25(OH) 2 D and regulating their in vivo levels and functions, 17,18 may also influence the obesity susceptibility in the human populations.…”

Section: Introductionmentioning

confidence: 99%

Association analysis of vitamin D-binding protein gene polymorphisms with variations of obesity-related traits in Caucasian nuclear families

et al. 2007

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Background: Vitamin D-binding protein (DBP) gene is well known for its function on glucose and vitamin D metabolism in human populations. Previous studies suggested that the in vivo DBP level may play a role in the etiology of obesity. However, few studies explored the contribution of DBP gene to the variance of obesity phenotypes. Objective: To investigate the relationship of DBP polymorphisms and obesity in Caucasian nuclear families. Design: We genotyped 14 single-nucleotide polymorphisms (SNPs) located in and around the DBP gene in 1873 Caucasian subjects from 405 nuclear families. Three obesity-related quantitative phenotypes were investigated, including body mass index (BMI), fat mass and percentage of fat mass (PFM). Single SNPs and haplotypes (three blocks) were tested by family-based association using the FBAT software. Results: SNP2 (rs17467825) and its corresponding haplotype GAA (frequency 0.270) in block1 showed strongest associations with PFM (P ¼ 0.0011 and 0.0023, respectively). In multivariate test significant association was also observed for SNP2 with fat_mass&BMI&PFM (P ¼ 0.0098). Subsequent sex-stratified analyses demonstrated nominal association for SNP2 and haplotype GAA with PFM in the female subgroup. Conclusion: Polymorphisms of DBP gene were significantly association with human PFM, especially in female, suggesting the importance of DBP gene in the pathogenesis of human obesity.

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“…These associations have been described by several authors, both in obese and non-obese patients [8,10,11,16,[18][19][20][21][22][23][24][25][26].…”

Section: Resultsmentioning

confidence: 69%

“…Other studies have reported vitamin D deficiencies in obese patients ranging from 41% to 93.8% [6,[10][11][12][13][14][15][16][17]. This wide range may be partly due to the differences in definition of vitamin D deficiency (Table 3).…”

Section: Resultsmentioning

confidence: 98%

Vitamin D Levels in an Obese Population, before and after Bariatric Surgery

Tavares¹,

Oliveira²,

Varela³

et al. 2016

Int J Clin Nutr Diet

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Background: Obesity has been associated with vitamin D deficiency. The purpose of this study was to evaluate vitamin D status in obese patients, before and after bariatric surgery, and to examine the relationship of 25(OH)D 3 levels with anthropometric measurements and body fat. Methods: Laboratory values of 25(OH)D 3 , anthropometric measurements, body fat and demographics were retrospectively collected from 239 obese patients, 179 of whom had undergone bariatric surgery. Blood levels of 25(OH)D 3 were correlated with anthropometric measurements, body fat, and with weight loss in patients undergone bariatric surgery. Results:The prevalence of vitamin D deficiency (<15ng/mL) was 50% in the non-operative group and 33% in the bariatric surgery group. A negative association was found between 25(OH)D 3 and anthropometric measurements and body fat in both groups. Body mass index, gender and season were predictors of 25(OH)D 3 . Each body mass index increase of 1 kg/m 2 was associated with a decrease of 0.5 ng/mL in 25(OH)D 3 . In addition, it was found a positive association between 25(OH)D 3 and weight loss after bariatric surgery. Conclusion:The levels of vitamin D seem to be associated with obesity. This finding suggests the need for assessment of vitamin D status and oral vitamin D supplementation in this population.

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Vitamin D Deficiency in the Morbidly Obese

Cited by 136 publications

References 0 publications

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

Association analysis of vitamin D-binding protein gene polymorphisms with variations of obesity-related traits in Caucasian nuclear families

Vitamin D Levels in an Obese Population, before and after Bariatric Surgery

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