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See 1 citation in J Clin Endocrinol Metab 2017:

J Clin Endocrinol Metab. 2017 Jul 1;102(7):2564-2574. doi: 10.1210/jc.2016-3591.

Impaired Release of Vitamin D in Dysfunctional Adipose Tissue: New Cues on Vitamin D Supplementation in Obesity.

Author information

1
Department of Medicine, Unit of Andrology and Reproductive Medicine, University of Padova, 35128 Padova, Italy.
2
Familial Tumor Unit, Veneto Institute of Oncology Istituto Oncologico Veneto-Istituto di Ricovero e Cura a Carattere Scientifico, 35128 Padova, Italy.
3
Laboratory of Protein Chemistry, Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35128 Padova, Italy.
4
Burn Unit and Plastic Surgery, University Hospital of Padova, 35128 Padova, Italy.
5
Department of Medicine, Internal Medicine, University of Padova, 35128 Padova, Italy.
6
Department of Medicine, Laboratory Medicine, University of Padova, 35128 Padova, Italy.

Abstract

Context:

Vitamin D accumulates in adipose tissue (AT), and vitamin D deficiency is frequent in obesity.

Objective:

We hypothesize that trafficking of vitamin D is altered in dysfunctional AT.

Design, Patients, Settings:

Fifty-four normal-weight and 67 obese males were recruited in a prospective study and randomly assigned to supplementation with 50 µg/wk 25-hydroxyvitamin-D3 or 150 µg/wk vitamin D3 for 1 year, raising dosage by 50% if vitamin D sufficiency [serum 25-hydroxyvitamin-D3 >50 nmol/L], was not achieved at 6 months; 97 subjects completed the study.

Methods:

Vitamin D3 and 25-hydroxyvitamin-D3 were quantified by HPLC-MS in control and insulin-resistant (IR) 3T3-L1 cells and subcutaneous AT (SAT) from lean and obese subjects, incubated with or without adrenaline; expression of 25-hydroxylase (Cyp27a1), 1α-hydroxylase (Cyp27b1), and vitamin D receptor (Vdr) was analyzed by real-time polymerase chain reaction.

Results:

In IR adipocytes, uptake of D3 and 25-hydroxyvitamin-D3 was higher, but, after adrenaline stimulation, the decrement in D3 and 25-hydroxyvitamin-D3 was stronger in control cells, which also showed increased expression of Cyp27a1 and Cyp27b1 and higher levels of 25-hydroxyvitamin-D3. In SAT from obese subjects, adrenaline-induced release of D3 and 25-hydroxyvitamin-D3 was blunted; in both IR cells and obese SAT, protein expression of β2-adrenergic receptor was reduced. Supplementation with 25-hydroxyvitamin-D3 was more effective in achieving vitamin D sufficiency in obese, but not in normal weight subjects.

Conclusion:

Dysfunctional AT shows a reduced catecholamine-induced release of D3 and 25-hydroxyvitamin-D3 and altered activity of vitamin D-metabolizing enzymes; for these reasons supplementation with 25-hydroxyvitamin-D3 is more effective in obese individuals.

PMID:
28187222
DOI:
10.1210/jc.2016-3591
[Indexed for MEDLINE]

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