Obesity is associated with lower concentrations of serum 25-hydroxyvitamin D; however, uncertainty exists as to the direction of causation. To date, meta-analyses of randomized controlled vitamin D-supplementation trials have shown no effect of raising circulating vitamin D on body weight, although several weight-loss-intervention trials have reported an increase in circulating vitamin D after weight reduction.
We undertook a systematic review and meta-analysis of randomized and nonrandomized controlled trials to determine whether weight loss compared with weight maintenance leads to an increase in serum 25-hydroxyvitamin D.
A systematic search for controlled weight-loss-intervention studies published up to 31 March 2016 was performed. Studies that included participants of any age with changes in adiposity and serum 25-hydroxyvitamin D as primary or secondary outcomes were considered eligible.
We identified 4 randomized controlled trials (n = 2554) and 11 nonrandomized controlled trials (n = 917) for inclusion in the meta-analysis. Random assignment to weight loss compared with weight maintenance resulted in a greater increase in serum 25-hydroxyvitamin D with a mean difference of 3.11 nmol/L (95% CI: 1.38, 4.84 nmol/L) between groups, whereas a mean difference of 4.85 nmol/L (95% CI: 2.59, 7.12 nmol/L) was observed in nonrandomized trials. No evidence for a dose-response effect of weight loss on the change in serum 25-hydroxyvitamin D was shown overall.
Our results indicate that vitamin D status may be marginally improved with weight loss in comparison with weight maintenance under similar conditions of supplemental vitamin D intake. Although additional studies in unsupplemented individuals are needed to confirm these findings, our results support the view that the association between obesity and lower serum 25-hydroxyvitamin D may be due to reversed causation with increased adiposity leading to suboptimal concentrations of circulating vitamin D. This trial was registered at www.crd.york.ac.uk/PROSPERO/ as CRD42015023836.
Pharmacology, Toxicology and Pharmaceutical Science
5
3%
Other
20
12%
Unknown
67
39%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 15. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 28 September 2021.
All research outputs
#3,277,865
of 34,410,315 outputs
Outputs from American Journal of Clinical Nutrition
#4,828
of 15,377 outputs
Outputs of similar age
#39,878
of 337,220 outputs
Outputs of similar age from American Journal of Clinical Nutrition
#58
of 107 outputs
Altmetric has tracked 34,410,315 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 90th percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 15,377 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 41.4. This one has gotten more attention than average, scoring higher than 68% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 337,220 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 88% of its contemporaries.
We're also able to compare this research output to 107 others from the same source and published within six weeks on either side of this one. This one is in the 45th percentile – i.e., 45% of its contemporaries scored the same or lower than it.
