Heading into Autumn Equinox, Vitamin D is Top of Mind (Again)
Have all the vitamin D researchers been on vacation? Who would believe that it has been almost a month since our last blog on vitamin D? Today’s blog highlights a new scientific report on the role of vitamin D in older adults. Takehome message: “Plasma 25(OH)D concentrations predict subsequent lower 13-y total mortality and incident cardiovascular disease, respiratory disease, and fractures.”
To be clear, despite the quote above, Khaw and colleagues are reporting a correlation not causal evidence. Serum (not plasma) samples were collected from 14,641 men and women (42-82 y, mostly white residents of Norfolk, UK in 1997-2000. [Wonder how the yes/no referendum is going? Is it still correct to refer to the United Kingdom?]. All volunteers were followed up (an average of 13y later) for health events. Total 25(OH)D concentrations were categorized into 5 groups: <30, 30 to <50, 50 to <70, 70 to <90 and ≥90 nmol/L. Mean 25(OH)D3 and 25(OH)D2 concentrations were 56.2 and 0.35 nmol/L, respectively. The differential in the respective blood levels is probably explained by the fact that less vitamin D2 (ergocalciferol) is consumed and ergocalciferol is not equivalent to cholecalciferol in maintaining vitamin D levels.
The most important insight is the dramatic change in relative risk (deaths) from respiratory disease and fractures with serum vitamin D concentration. It is not surprising that one of the first vitamin D – health outcomes reported was trunk muscle strength and body sway which is associated with the risk of falls and fractures.
Because of global vitamin D insufficiency, dietary supplementation could be a cost-effective measure to reduce the risk of many diseases. Because of the strong link between vitamin D status and lung function, it is not surprising to see a significant association with death from respiratory disease. Higher serum 25(OH)D concentrations are associated with lower risk of breast cancer. Low vitamin D status is associated with increased risk of cardiovascular events and vitamin D supplementation (800 IU daily) appears protective.
So there you have it. Although it has been almost a month, scientists have given us justification (again) to spend time in the sunshine and/or use a vitamin D supplement.
Khaw K-T, Luben R, Wareham N. Serum 25-hydroxyvitamin D, mortality, and incident cardiovascular disease, respiratory disease, cancer, and fractures: a 13-y prospective population study. 2014 Am J Clin Nutr doi: 10.3945/ajcn.114.086413
Pfeifer M, Begerow B, Minne HW, Schlotthauer T, Pospeschill M, Scholz M, Lazarescu AD, Pollahne W. Vitamin D status, trunk muscle strength, body sway, falls, and fractures among 237 postmenopausal women with osteoporosis. 2001 Exp Clin Endocrinol Diab doi: 10.1055/s-2001-14831
Bischoff HA, Stahelin HB, Dick W, Akos R, Knecht M, Salis C, Nebiker M, Theiler R, Pfeifer M, Begerow B, Lew RA, Conzelmann M. Effects of vitamin D and calcium supplementation on falls: A randomized controlled trial. 2003 JBMR doi: 10.1359/jbmr.2003.18.2.343
Hughes DA, Norton R. Vitamin D and respiratory health. 2009 Clin Exper Immunol doi: 10.1111/j.1365-2249.2009.04001.x
McDonnell S, French C, Gorham E, Garland C. 25(OH)D serum levels ≤ 50 ng/mL may provide additional reduction in breast cancer risk. 2014 FASEB J 28:(1) S628.12
Ford JA, MacLennan GS, Avenell A, Bolland M, Grey A, Witham M, for the RECORD trial group. Cardiovascular disease and vitamin D supplementation: trial analysis, systematic review, and meta-analysis. 2014 Am J Clin Nutr doi: 10.3945/ajcn.113.082602