Deposition in and release of vitamin D3 from body fat: evidence for a storage site in the rat

Rosenstreich, Saul J.; Rich, Charles L.; Volwiler, Wade

doi:10.1172/jci106538

Cited by 250 publications

(137 citation statements)

References 28 publications

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“…Obese individuals have a lower circulating 25(OH)D concentration than those of normal weight (19)(20)(21)(22)(23) . However, in adult males living in subtropical China, we did not find a significantly lower vitamin D status in the obese group.…”

Section: Discussionmentioning

confidence: 98%

Oral vitamin D supplementation has a lower bioavailability and reduces hypersecretion of parathyroid hormone and insulin resistance in obese Chinese males

Zhou

Zhu²,

Chen³

et al. 2014

Public Health Nutr.

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Objective: To examine the vitamin D status, SNP of the vitamin D receptor gene (VDR) and the effects of vitamin D supplementation on parathyroid hormone and insulin secretion in adult males with obesity or normal weight in a subtropical Chinese city. Design: An intervention trial. Setting: Shenzhen City, Guangdong Province, China. Subjects: From a cross-sectional survey conducted from June to July, eighty-two normal-weight and ninety-nine obese males (18-69 years) were screened to analyse their vitamin D status and for five SNP of VDR. From these individuals, in the same season of a different year, obese and normal-weight male volunteers (twenty-one per group) were included for an intervention trial with oral vitamin D supplementation at 1250 µg/week for 8 weeks.Results: For the survey, there was no significant difference (P > 0·05) in baseline circulating 25-hydroxyvitamin D concentrations or in the percentages of participants in different categories of vitamin D status between the two groups. The VDR SNP, rs3782905, was significantly associated with obesity (P = 0·043), but none of the examined SNP were correlated with serum 25-hydroxyvitamin D when adjusted for age, BMI and study group. After vitamin D supplementation, serum 25-hydroxyvitamin D concentration, hypersecretions of parathyroid hormone and insulin, and insulin resistance in the obese were changed beneficially (P < 0·05); however, the increase in serum 25-hydroxyvitamin D was less than that of the normal-weight men. Conclusions: For obese and normal-weight men of subtropical China, the summer baseline vitamin D status was similar. However, oral vitamin D supplementation revealed a decreased bioavailability of vitamin D in obese men and ameliorated their hypersecretion of parathyroid hormone and insulin resistance. KeywordsVitamin D Obesity Chinese male Parathyroid hormone Insulin resistanceIn China, approximately 12 % of adult males are considered to be obese (1,2) . Since vitamin D nutritional status may be important in regulating obesity (3)(4)(5)(6) , interest was aroused to study Chinese obese males in this regard. Circulating 25-hydroxyvitamin D (25(OH)D; calcidiol), a metabolite of vitamin D having a half-life of 2-3 weeks, is recommended as a reliable marker of vitamin D nutritional status (7)(8)(9)(10) . The US Institute of Medicine (11) reports that a circulating 25(OH)D concentration equal to 50 nmol/l (20 ng/ml) meets the vitamin D requirements of 97·5 % of the population, and this threshold is widely accepted for hypovitaminosis D (10,(12)(13)(14) . Not satisfied with that basic requirement, many researchers claim that improvement of circulating 25(OH)D concentrations to much higher than 50 nmol/l can prevent a broad range of diseases (4,(15)(16)(17) .In addition, 25(OH)D ≤25 nmol/l (10 ng/ml) is considered to be 'severe vitamin D deficiency', 75-250 nmol/l (30-100 ng/ml) a 'sufficient or optimal' level and 50-75 nmol/l (21-29 ng/ml) an 'insufficient' level (12,13,18) , although these reference ranges are not defined by the Inst...

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Section: Discussionmentioning

confidence: 98%

Oral vitamin D supplementation has a lower bioavailability and reduces hypersecretion of parathyroid hormone and insulin resistance in obese Chinese males

Zhou

Zhu²,

Chen³

et al. 2014

Public Health Nutr.

View full text Add to dashboard Cite

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“…[24][25][26][27] 25-Hydroxyvitamin D is the dominant circulating form of VD, and the best indicator of VD status. 8 The formation, activation and catabolism of 25OHD is a complex process, which involves the mitochondrial and microsomal cytochrome P450 enzymes.…”

Section: Introductionmentioning

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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“…The relationship between VtD and body fat was described originally by Lumb et al [1]. Subsequently murine experiment and human study revealed that body fat is the major storage site of vitamin D3 and the source for other VtD metabolites during deprivation as well [2,3]. The reasons of VtD insuffi ciency in obese people have been postulated to several factors such as a decrease exposure to sunlight because of low activity level, a negative feedback from elevated active VtD metabolite 1,25-hydroxyvitamin D and parathyroid hormone (PTH) levels on hepatic synthesis of 25-OHD [4], and the metabolic clearance of VtD may increase in obesity with enhanced uptake by adipose tissue [5].…”

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confidence: 95%

25-hydroxyvitamin D levels and body mass index in healthy postmenopausal women

Jang

Lee

Bae

et al. 2012

Korean J Obstet Gynecol

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Vitamin D (VtD) endocrine system is associated with obesity. The relationship between VtD and body fat was described originally by Lumb et al. [1]. Subsequently murine experiment and human study revealed that body fat is the major storage site of vitamin D3 and the source for other VtD metabolites during deprivation as well [2,3]. The reasons of VtD insuffi ciency in obese people have been postulated to several factors such as a decrease exposure to sunlight because of low activity level, a negative feedback from elevated active VtD metabolite 1,25-hydroxyvitamin D and parathyroid hormone (PTH) levels on hepatic synthesis of 25-OHD [4], and the metabolic clearance of VtD may increase in obesity with enhanced uptake by adipose tissue [5]. Recently, Worstman et al. [6] also demonstrated that obesity-associated VtD insuffi ciency most likely ORIGINAL ARTICLE Korean J Obstet Gynecol 2012;55(6) Objective Obesity is associated with alterations in vitamin D (VtD) system. We evaluated the correlation between VtD level and body mass index (BMI), a standard for the evaluation of obesity in postmenopausal women. MethodsTo study the relationship between VtD levels and obesity, we recruited 310 healthy postmenopausal women between January 2005 and March 2011 and analyzed the correlation between BMI and serum 25-hydroxyvitamin D (25-OH-VtD) level. We also analyzed the relationship between serum VtD level and bone health status such as bone mineral density measured by dual-energy X-ray absorptiometry, bone turnover marker, and parathyroid hormone (PTH). ResultsWith a cut-off level for VtD deficiency at 30 ng/mL, 98.9% patients showed a VtD deficiency, while 87.8% patients showed a vitamin D defi ciency with a 20-ng/mL cut-off level. VtD levels had no signifi cant correlation with age, height, weight, BMI, or bone turnover markers. PTH level and serum 25-OH-VtD level showed a negative correlation. VtD level showed negative correlation with BMI, but statistically not signifi cant. ConclusionIn this study, most of postmenopausal women (more than 87.8%) had a VtD defi ciency, and VtD level showed negative correlation with BMI, but was not statistically signifi cant.

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Deposition in and release of vitamin D3 from body fat: evidence for a storage site in the rat

Cited by 250 publications

References 28 publications

Oral vitamin D supplementation has a lower bioavailability and reduces hypersecretion of parathyroid hormone and insulin resistance in obese Chinese males

Oral vitamin D supplementation has a lower bioavailability and reduces hypersecretion of parathyroid hormone and insulin resistance in obese Chinese males

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

25-hydroxyvitamin D levels and body mass index in healthy postmenopausal women

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