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Providing perspectives on recent research into vitamins and nutritionals


Vitamin D, Inflammation, Biomarkers and Weight Loss

By Michael McBurney

Inflammation, especially chronic inflammation, has been linked with cardiovascular disease and metabolic syndrome-associated disorders (obesity, insulin resistance, type 2 diabetes, and hepatic steatosis). Maternal inflammation during pregnancy can even affect the health of a child.

Elevated C-reactive protein (CRP) concentrations are a marker of inflammation. CRP concentrations increase in response to infections, inflammation, and oxidative stress.  Eating a diet lacking adequate amounts of omega-3 fatty acids, especially DHA and EPA, is associated with higher CRP concentrations. Vitamin D supplementation increases serum 25(OH)D3 concentrations and reduces CRP concentrations.

Because vitamin D deficiency is associated with obesity, Mason and colleagues hypothesized that vitamin D3 supplementation (2000 IU daily) in overweight/obese women (n = 218) with low serum 25(OH)D concentrations might be beneficial. At baseline, serum 25(OH)D3 levels averaged 21.4 ng/mL  (53.5 nmol/L). So they were sufficient (> 50 nmol/L) according to IOM recommendations but they spent, on average, 2.2 to 2.5 hours in the sun! This is not typical. Of course, vitamin D status could be lower because ~50% of participants reported using sunscreen as often reported for this age group. Over the course of 12 months, vitamin D dietary intake (averaging 263-364 IU/d; see Supplement 1) did not change. And, as expected, was considerably below IOM recommendations (600 IU/d). Both interventions (placebo and supplementation) had similar average weight loss over 12 months. However, women whose vitamin D status became replete with supplementation (vs those who didn't), lost more weight, had a greater waist circumference reduction, and lost a greater percent of body fat.

In an interview, Dr McTiernan, a co-author said, “This suggests women trying to lose weight might want their D levels checked by their provider and replenish vitamin D levels either through supplements or sun and then have their D levels rechecked after a few months to make sure they have risen to a healthy level.

Thank you Dr McTiernan. Such good advice – using biological sampling to determine need, to advise on options - more sun exposure, dietary change or dietary supplementation – and to achieve optimal nutrient status. Here’s to greater adoption of biomarkers for peace of mind.

Main Citation

Mason C, Xiao L, Imayama I, Duggan C, Wang C-Y, Korde L, McTiernan A. Vitamin D3 supplementation during weight loss: a double-blind randomized controlled trial. 2014 Am J Clin Nutr doi: 10.3945/ajcn.113.073734

Other Citations

Asemi Z, Samimi M, Tabassi Z, Shakeri H, Esmaillzadeh A. Vitamin D supplementation affects serum high-sensitivity C-reactive protein, insulin resistance, and biomarkers of oxidative stress in women. 2013 J Nutr doi: 10.3945/​jn.113.177550

Reinders I, Virtanen JK, Brouwer A, Tuomainen T-P. Associations of serum n-3 polyunsaturated fatty acids with C-reactive protein in men. 2012 Eur J Clin Nutr doi:10.1038/ejcn/2011.195