Thursday, February 05, 2009
Sunday, February 01, 2009
Relationships of low serum vitamin D3 with anthropometry and markers of the metabolic syndrome and diabetes in overweight and obesity
Relationships of low serum vitamin D3 with anthropometry and markers of the metabolic syndrome and diabetes in overweight and obesity
Conversion of vitamin D3 to its derivative 1,25 vitamin D3 is complex and involves other hormones. 1,25 vitamin D3, via its receptor which is present in insulin-producing beta-islet cells, is known to be a potent regulator of cell proliferation and differentiation [22,23]. However, there is evidence that low vitamin D3 itself is associated with TIIDM irrespective of 1,25 vitamin D3 [8]. The inverse relationship of vitamin D3 with high to extreme HbA1c [24,25] and/or FPG [7,8] may indicate that it is the long-term, severely abnormal (carbohydrate) metabolism of TIIDM [7,26,27] and muscle insulin resistance [28], that is associated with hypovitaminosis D3. HbA1c, a glycated protein, is a predictor of 2-hour glucose in oral glucose tolerance testing, [29] an indicator of chronic hyperglycaemia, protein glycation damage [30] and oxidative stress [31]. Many new, profound and interacting mechanisms link hypovitaminosis D with other correlates of the metabolic syndrome, including renin regulation [1]. Vitamin D-upregulated protein-1 reportedly modulates endothelial oxidative stress, macrophage and smooth muscle function, depending on the stage of atherosclerosis [32,33].
Limitations of the present study include the cross sectional design where cause cannot be attributed. Lifestyle, body shape sensitivity [34,35] or cultural reasons [36] for precluding skin exposure to view, and ultraviolet light for efficient vitamin D3 synthesis, may selectively affect obese people but were not examined.
In the current study low serum vitamin D3 was inversely related to weight and BMI, but not fat mass, and to markers indicative of TIIDM (large waist and raised HbA1c), rather than MetSyn per se. The link between hypovitaminosis D3 and metabolic disorders, including obesity, MetSyn, TIIDM and CVD requires further investigation, particularly for those most at risk of these combined conditions.
Conversion of vitamin D3 to its derivative 1,25 vitamin D3 is complex and involves other hormones. 1,25 vitamin D3, via its receptor which is present in insulin-producing beta-islet cells, is known to be a potent regulator of cell proliferation and differentiation [22,23]. However, there is evidence that low vitamin D3 itself is associated with TIIDM irrespective of 1,25 vitamin D3 [8]. The inverse relationship of vitamin D3 with high to extreme HbA1c [24,25] and/or FPG [7,8] may indicate that it is the long-term, severely abnormal (carbohydrate) metabolism of TIIDM [7,26,27] and muscle insulin resistance [28], that is associated with hypovitaminosis D3. HbA1c, a glycated protein, is a predictor of 2-hour glucose in oral glucose tolerance testing, [29] an indicator of chronic hyperglycaemia, protein glycation damage [30] and oxidative stress [31]. Many new, profound and interacting mechanisms link hypovitaminosis D with other correlates of the metabolic syndrome, including renin regulation [1]. Vitamin D-upregulated protein-1 reportedly modulates endothelial oxidative stress, macrophage and smooth muscle function, depending on the stage of atherosclerosis [32,33].
Limitations of the present study include the cross sectional design where cause cannot be attributed. Lifestyle, body shape sensitivity [34,35] or cultural reasons [36] for precluding skin exposure to view, and ultraviolet light for efficient vitamin D3 synthesis, may selectively affect obese people but were not examined.
In the current study low serum vitamin D3 was inversely related to weight and BMI, but not fat mass, and to markers indicative of TIIDM (large waist and raised HbA1c), rather than MetSyn per se. The link between hypovitaminosis D3 and metabolic disorders, including obesity, MetSyn, TIIDM and CVD requires further investigation, particularly for those most at risk of these combined conditions.
Novel pathways that contribute to the anti-prolife...[J Steroid Biochem Mol Biol. 2007] - PubMed Result
Novel pathways that contribute to the anti-proliferative and chemopreventive activities of calcitriol in prostate cancer. [J Steroid Biochem Mol Biol. 2007] - PubMed Result
"Thus, we conclude that calcitriol [Vitamin D3] regulates myriad pathways that contribute to the potential chemopreventive and therapeutic utility of calcitriol in prostate cancer (PCa.)"
"Thus, we conclude that calcitriol [Vitamin D3] regulates myriad pathways that contribute to the potential chemopreventive and therapeutic utility of calcitriol in prostate cancer (PCa.)"
Calcium, Dairy Foods, Vitamin D, and Colorectal Cancer Risk: The Fukuoka Colorectal Cancer Study -- Mizoue et al. 17 (10): 2800 -- Cancer Epidemiology Biomarkers & Prevention
Calcium, Dairy Foods, Vitamin D, and Colorectal Cancer Risk: The Fukuoka Colorectal Cancer Study -- Mizoue et al. 17 (10): 2800 -- Cancer Epidemiology Biomarkers & Prevention
"A decreased risk of colorectal cancer associated with high calcium intake was observed among those who had higher levels of vitamin D intake or among those who had a greater chance of daily sunlight exposure, but not among those with medium or lower intake of vitamin D or among those with potentially decreased sunlight exposure. These results add to support for a joint action of calcium and vitamin D in the prevention of colorectal carcinogenesis." (Cancer Epidemiol Biomarkers Prev 2008;17(10):2800–7)
"A decreased risk of colorectal cancer associated with high calcium intake was observed among those who had higher levels of vitamin D intake or among those who had a greater chance of daily sunlight exposure, but not among those with medium or lower intake of vitamin D or among those with potentially decreased sunlight exposure. These results add to support for a joint action of calcium and vitamin D in the prevention of colorectal carcinogenesis." (Cancer Epidemiol Biomarkers Prev 2008;17(10):2800–7)
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