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Plasma 25-hydroxyvitamin d is associated with markers of the insulin resistant phenotype in nondiabetic adults. Liu E, Meigs JB, Pittas AG, McKeown NM, Economos CD, Booth SL, Jacques PF. J Nutr. 2009 Feb;139(2):329-34. Epub 2008 Dec 23. PMID: 19106328 doi:10.3945/jn.108.093831 After adjusting for age and sex, plasma 25(OH)D was positively associated with ISI(0,120), plasma adiponectin, and HDL cholesterol and inversely associated with plasma triacylglycerol, but these associations were no longer significant after further adjustment for BMI, waist circumference, and current smoking status. 25(OH)D and 2-h post-OGTT glucose were not associated. Among adults without diabetes, vitamin D status was inversely associated with surrogate fasting measures of insulin resistance. These results suggest that vitamin D status may be an important determinant for type 2 diabetes mellitus.

Vitamin D metabolites as clinical markers in autoimmune and chronic disease. Blaney GP, Albert PJ, Proal AD. Ann N Y Acad Sci. 2009 Sep;1173:384-90. PMID: 19758177 DOI: 10.1111/j.1749-6632.2009.04875.x

Vitamin D supplementation enhances the beneficial effects of weight loss on cardiovascular disease risk markers. Zittermann A, Frisch S, Berthold HK, Götting C, Kuhn J, Kleesiek K, Stehle P, Koertke H, Koerfer R. Am J Clin Nutr. 2009 May;89(5):1321-7. Epub 2009 Mar 25. PMID: 19321573

Pittas AG, Harris SS, Stark PC, Dawson-Hughes B. The Effects of Calcium and Vitamin D Supplementation on Blood Glucose and Markers of Inflammation in Non-diabetic Adults. Diabetes Care. 2007 Feb 2; [Epub ahead of print] PMID: 17277040 [PubMed - as sup

A positive dose-response effect of vitamin D supplementation on site-specific bone mineral augmentation in adolescent girls: a double-blinded randomized placebo-controlled 1-year intervention. Viljakainen HT, Natri AM, Kärkkäinen M, Huttunen MM, Palssa A, Jakobsen J, Cashman KD, Mølgaard C, Lamberg-Allardt C. J Bone Miner Res. 2006 Jun;21(6):836-44. PMID: 16753014 doi: 10.1359/jbmr.060302 We conclude that the current vitamin D recommendation for adolescent girls, at least in the northern latitudes, is too low to ensure sufficient vitamin D status during winter. Intake of vitamin D at rates of 10-15 μg/day aids to maintain stable S-25(OH)D concentrations during winter. Vitamin D induced BMC augmentation by decreasing bone resorption, but not affecting bone formation, which was reflected by the biochemical markers of bone turnover. Optimizing bone mineral gain in adolescence is crucial to the prevention of osteoporosis later in life. Increasing vitamin D intake to 10-15 μg/day aids in attaining this goal.

A German group has now shown that the important inflammatory marker, tumor necrosis factor (TNF), is also reduced by vitamin D supplementation. Many studies have implicated increased TNF levels in promoting cancer. In this study, a modest vitamin D dose of 3320 units (83 micrograms) was given vs. placebo. The 25-hydroxy D level reached in the treated group was 34.2 ng/ml (85.5 nmol/L), which resulted in a 26.5% reduction in TNF compared with 18.7% reduction (?) in the placebo group.

A seasonal variation of calcitropic hormones, bone turnover and bone mineral density in early and mid-puberty girls - a cross-sectional study. Viljakainen HT, Palssa A, Kärkkäinen M, Jakobsen J, Cashman KD, Mølgaard C, Lamberg-Allardt C. Br J Nutr. 2006 Jul;96(1):124-30. PMID: 16870000 Seasonal variation in S-25-OHD and bone remodelling markers accompanied by negative correlation between S-25-OHD and S-iPTH was seen in this cross-sectional study of adolescent girls. In addition, the seasonal rhythm contributed 7.0-7.6 % difference in the BMD of lumbar vertebrae and left femur in early puberty girls. This variation should be avoided since it could hamper peak bone mass attainment.

Serum 25-hydroxyvitamin D3 concentrations and carotid artery intima-media thickness among type 2 diabetic patients. Targher G, Bertolini L, Padovani R, Zenari L, Scala L, Cigolini M, Arcaro G. Clin Endocrinol (Oxf). 2006 Nov;65(5):593-7. PMID: 17054459 DOI: 10.1111/j.1365-2265.2006.02633.x CONCLUSIONS: Hypovitaminosis D is highly prevalent in type 2 diabetic adults and is strongly and independently associated with increased carotid IMT. Further investigation into whether vitamin D may play a role in the prevention of atherosclerosis appears to be warranted. In conclusion, our results show that type 2 diabetic adults have significant reductions in serum 25(OH)D concentrations (vs matched controls) that predict preclinical atherosclerosis, independent of classical risk factors, renal function tests, inflammatory markers, use of medications and presence of the metabolic syndrome. These findings suggest the need for ongoing evaluation of the possible protective role of vitamin D3 supplementation in the development of atherosclerosis.

Fatigue fractures in military conscripts : A study on risk factors, diagnostics and long-term consequences Ruohola, Juha-Petri University of Helsinki, Faculty of Medicine, Institute of Clinical Medicine, Orthopaedics and Traumatology, Helsinki University Central Hospital Centre of Military Medicine, Helsinki 2007-03-09 Doctoral dissertation (article-based) It seems likely that low vitamin D levels are related to fatigue fractures, and that an increasing trend exists between TRACP-5b bone resorption marker elevation and fatigue fracture incidence. Though seldom detected by plain radiography, fatigue fractures often underlie unclear lower leg stress-related pain occurring in the distal parts of the tibia. Femoral neck fatigue fractures, when displaced, lead to long-term morbidity in a high percentage of patients, whereas, when non-displaced, they do not predispose patients to subsequent adverse complications. Importantly, an educational intervention can diminish the incidence of fracture displacement by enhancing awareness and providing instructions for earlier diagnosis of fatigue fractures

Association between serum 25(OH)D and death from prostate cancer. Tretli S, Hernes E, Berg JP, Hestvik UE, Robsahm TE. Br J Cancer. 2009 Feb 10;100(3):450-4. Epub 2009 Jan 20. PMID: 19156140 doi:10.1038/sj.bjc.6604865 The serum level of 25(OH)D may be involved in disease progression and is a potential marker of prognosis in patients with prostate cancer.

"I discussed in my last post how Dr Vieth has a model of tissue 1,25(OH)2D synthesis and degradation in which the level of active substance is pretty well independent of blood vitamin D level, provided the level is either rising or stable. I think it is also worth pointing out that he is talking, hypothetically, about tissue 1,25(OH)2D, not plasma level... As we know, almost nothing is known about tissue 1,25(OH)2D control. By Vieth's hypothesis tissue 1,25(OH)2D is OK so long as there is at least SOME vitamin D present in plasma and the level dose not vary too much. Obviously there is a level below which you can have as much of the enzyme for converting vitamin D to the active form as you like, if there is no vitamin D in your blood you can't make any 1,25(OH)2D in your tissues, or in your kidneys for export to your blood to control calcium levels. At the lower extremes we have rickets and osteomalacia. These are clear cut, unarguable markers of vitamin D deficiency, in the absence of confounding factors (there are a few)."

"We are aware of substantial scientific evidence supporting the role of vitamin D in prevention of cancer. It has been reasonably established that adequate serum vitamin D metabolite levels are associated with substantially lower incidence rates of several types of cancer, including those of the breast, colon, and ovary, and other sites. We have concluded that the vitamin D status of most individuals in North America will need to be greatly improved for substantial reduction in incidence of cancer. Epidemiological studies have shown that higher vitamin D levels are also associated with lower risk of Type I diabetes in children and of multiple sclerosis. Several studies have found that markers of higher vitamin D levels are associated with lower incidence and severity of influenza and several other infectious diseases."

VITAMIN D LOWERS C-REACTIVE PROTEIN (CRP) Van den Berghe and colleagues at the University of Leuven in Belgium appear to be the first to show that simple, natural and cheap vitamin D (cholecalciferol) lowers CRP in critically ill patients. Even small amounts of cholecalciferol (500 IU) lowered CRP by more than 25% in a small group of critically ill patients. Another marker of inflammation (IL-6) was reduced even more. The researchers also found that critically ill patients were profoundly deficient in vitamin D.

A phase 2 trial exploring the effects of high-dose (10,000 IU/day) vitamin D(3) in breast cancer patients with bone metastases. Amir E, Simmons CE, Freedman OC, Dranitsaris G, Cole DE, Vieth R, Ooi WS, Clemons M. Cancer. 2009 Nov 13. [Epub ahead of print] PMID: 19918922 DOI: 10.1002/cncr.24749 METHODS: Patients with bone metastases treated with bisphosphonates were enrolled into this single-arm phase 2 study. Patients received 10,000 IU of vitamin D3 and 1000 mg of calcium supplementation each day for 4 months. The effect of this treatment on palliation, bone resorption markers, calcium metabolism, and toxicity were evaluated at baseline and monthly thereafter. CONCLUSIONS: Daily doses of 10,000 IU vitamin D3 for 4 months appear safe in patients without comorbid conditions causing hypersensitivity to vitamin D. Treatment reduced inappropriately elevated parathyroid hormone levels, presumably caused by long-term bisphosphonate use. There did not appear to be a significant palliative benefit nor any significant change in bone resorption. Cancer 2010. © 2009 American Cancer Society.

The same annual dose of 292 000 IU of vitamin D(3) (cholecalciferol) on either daily or four monthly basis for elderly women: 1-year comparative study of the effects on serum 25(OH)D(3) concentrations and renal function. Pekkarinen T, Välimäki VV, Aarum S, Turpeinen U, Hämäläinen E, Löyttyniemi E, Välimäki MJ. Clin Endocrinol (Oxf). 2009 May 25. [Epub ahead of print] PMID: 19486025 DOI: 10.1111/j.1365-2265.2009.03637.x