The relative absorption of a standardized curcuminoid mixture and its corresponding lecithin formulation (Meriva) was investigated in a randomized, double-blind, crossover human study. Clinically validated dosages were used for both products, and plasma levels of all three major curcuminoids [curcumin (1a), demethoxycurcumin (1b), and bisdemethoxycurcumin (1c)] were evaluated. Total curcuminoid absorption was about 29-fold higher for Meriva than for its corresponding unformulated curcuminoid mixture, but only phase-2 metabolites could be detected, and plasma concentrations were still significantly lower than those required for the inhibition of most anti-inflammatory targets of curcumin. Remarkably, phospholipid formulation increased the absorption of demethoxylated curcuminoids much more than that of curcumin (1a), with significant differences in plasma curcuminoid profile between Meriva and its corresponding unformulated curcuminoid mixture. Thus, the major plasma curcuminoid after administration of Meriva was not curcumin (1a), but demethoxycurcumin (1b), a more potent analogue in many in vitro anti-inflammatory assays. The improved absorption, and possibly also a better plasma curcuminoid profile, might underlie the clinical efficacy of Meriva at doses significantly lower than unformulated curcuminoid mixtures.
BackgroundTranscription of the cathelicidin antimicrobial peptide (CAMP) gene is induced by binding of the bioactive form of vitamin D, 1,25-dihydroxyvitamin D, to the vitamin D receptor. Significant levels of the protein hCAP18/LL-37 are found in the blood and may protect against infection and/or sepsis. We hypothesized that serum vitamin D levels may modulate the circulating levels of hCAP18. Only three studies have shown a positive correlation between circulating 25-hydroxyvitamin D and hCAP18 levels. Here we provide additional evidence for such a correlation in healthy, middle-aged adults.FindingsSerum levels of 25-hydroxyvitamin D [25(OH)D] and plasma levels of hCAP18 were determined in 19 healthy middle-aged (mean of 50.1 years) adult men and women. Plasma hCAP18 concentrations correlated with serum 25(OH)D concentrations in subjects with 25(OH)D levels ≤ 32 ng/ml (r = 0.81, p < 0.005) but not in subjects with concentrations > 32 ng/ml (r = 0.19, p = 0.63).ConclusionsWe conclude that plasma hCAP18 levels correlate with serum 25(OH)D levels in subjects with concentrations of 25(OH)D ≤ 32 ng/ml as opposed to those with concentrations > 32 ng/ml and that vitamin D status may regulate systemic levels of hCAP18/LL-37.
Vitamin D supplementation was the most significant positive predictor of vitamin D status. Collectively, these data point to the practicality of utilizing vitamin D supplements to reduce hypovitaminosis D in adults throughout the United States.
Recent evidence suggests that circulating vitamin D levels above the current RDA (20ng/ml) may be associated with better health outcomes. However, many factors impact vitamin D status, but their influence on serum levels of 25(OH)D remains unclear. In this retrospective, cross‐sectional study, we sought to identify predictor variables of vitamin D status in free living subjects. Serum levels of 25(OH)D were measured, and the variables gender, ethnicity, height, weight, age, geographic location, duration of daily sun exposure, use of sunscreen and sun‐obscuring clothing, dietary intake, supplement usage, latitude of residence and BMI were used to predict vitamin D status in a summer and winter cohort of subjects. Supplemental vitamin D3 intake was the most significant positive predictor ‐ whereas BMI was the most significant negative predictor ‐ of vitamin D status in both the summer and winter cohort. Additional positive predictors were fortified beverage consumption in the summer, and dairy consumption in the winter. Negative predictors were African American and Asian ethnicity in the summer, while latitude of residence >;36°N and Asian ethnicity were negative predictors in the winter. These results indicate that vitamin D supplementation is the most significant positive predictor of vitamin D status, and point to the practicality of utilizing vitamin D supplements to reduce hypovitaminosis D.
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