forms, may play a role in promotion of weight loss in obese patients,
perhaps through effects on adipose metabolism, according to research
reported Thursday at The Endocrine Society's annual meeting in
Washington, D.C.
While vitamin D deficiency is associated with obesity, "there are
limited data on the temporal relationship between vitamin D and weight
loss -- an important step in establishing a cause-effect link between
vitamin D deficiency and obesity," Dr. Shalamar Sibley from the
University of Minnesota in Minneapolis told the conference.
She and colleagues investigated the temporal relationship between
baseline vitamin D levels and subsequent weight loss success in 38
overweight and obese men and women.
They measured plasma vitamin D (25-hydroxyvitamin D and
1,25-dihydroxyvitamin D) concentrations before and after an 11-week
weight loss intervention consisting of a 750 calorie per day deficit
from estimated total daily calorie needs. They used dual-energy X-ray
absorptiometry and computed tomography to measure body composition and
fat distribution.
On average, vitamin D levels in study subjects were in the insufficient
range.
According to the investigators, in separate models adjusted for gender,
baseline (pre-diet) 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D
levels predicted subsequent weight loss success (p = 0.020 and p =
0.015, respectively) on a reduced calorie diet.
For each 1-ng/mL increase in level of 25-hydroxyvitamin D, obese
patients lost almost half a pound (0.196 kg) more on their
calorie-restricted diet. For each 1-ng/mL increase in
1,25-dihydroxyvitamin D, subjects lost nearly one-quarter pound (0.107
kg) more.
"Abdominal fat loss, in particular, tended to be related to baseline
vitamin D concentrations, with the effect being stronger with the active
form of vitamin D," Dr. Sibley reported. "Vitamin D status did not
predict lean body mass changes, so there was relative preservation of
lean tissue."
The researchers say studies are needed to confirm these findings and
define underlying mechanisms.
"If it is established," Dr. Sibley said, "that vitamin D does indeed
synergistically contribute to standard weight loss approaches, such as a
reduced calorie diet, then identification and treatment of inadequate
vitamin D status could ultimately have a large public health impact on
the obesity epidemic. Our findings suggest that vitamin D may play an
important role in promoting optimal weight management," she concluded.
From Reuters Health, by Megan Rauscher
Reviewed / Posted by: Scott W. Yates, MD, MBA, MS, FACP
