Glass Half Full or Half Empty: Vitamin D and other Nutrients
There is a proverb “Health is merely the slowest possible rate at which one can die”. Personally, I prefer the words of the Dutch Renaissance scholar, Desiderius Erasmus, “Prevention is better than the cure” because it emphasizes stability rather than a slow, torturous decline.
Cardiovascular disease is a consequence of inflammation, malnutrition and atherosclerosis. Genetics also play a role. Cardiovascular disease typically progresses for years before being clinically diagnosed. The practice of medicine is initiated by a cataclysmic event, i.e. a heart attack, or a life-changing assessment, i.e. a diagnosis of hypercholesterolemia. Because we eat foods for many reasons - hunger, boredom, to be sociable, etc., nutrition, behavior and health are intricately entwined. This medley makes it very difficult to attribute specific health events to a single nutrient.
For years fat, especially saturated fat and cholesterol, were the nutritional villains of cardiovascular disease. In his 1975 paper, Ancel Keyes identified the challenge of attributing cause to the intake of fat or sugar with coronary heart disease (CHD) mortality. He correlated CHD mortality with both sugar and fat intake; yet he wrote, “However, partial correlation analysis shows that when sugar is held constant, CHD is highly correlated with per capita saturated fats in the diet but when fat is constant there is no significant correlation between sugar in the diet and the CHD incidence rates.”
The difficulty in teasing apart and assigning values to specific macro- or micronutrients lies in the fact that changing dietary patterns affect the intake of multiple items - fat, sugar, protein, vitamins and minerals. Moreover, genetics may trump nutrition for some when it comes to cholesterol (LDL-C) concentrations.
So don’t be surprised to read that vitamin D deficiency may not cause heart disease. Vitamin deficiencies cause disease but health consequences of excessive intakes are rare (see yesterday’s blog for an example). By not consuming enough vitamins to maintain normal blood levels, the function of cells in our body may be compromised. As noted by the 2015 Dietary Guidelines Advisory Committee, suboptimal dietary patterns are causally related to poor individual health and higher chronic disease rates.
Many are vitamin D insufficient because we do not spend time outdoors. And when we are outside, we use sunscreens to reduce the risk of sunburn and skin cancer. To maintain blood vitamin D concentrations [serum 25(OH)D] above recommendations (≥50 nmol/L) under these circumstances, we need to consume more vitamin D. See the NIH-ODS website for sources of vitamin D.
To learn more about factors affecting blood vitamin D concentrations, see the review article by Mazahery and von Hurst. Don’t think about vitamin D, or any other vitamin, as the panacea for health.
Collectively, vitamins and minerals are essential to support the structure and function of our bodies for a long, long, long time.
Mazahery H, von Hurst PR. Factors affecting 25-hydroxyvitamin D concentration in response to vitamin D supplementation. 2015 Nutrients doi: 10.3390/nu7075111
Pecoits-Filho R, Lindholm B, Stenvinkel P. The malnutrition, inflammation, and atherosclerosis (MIA) syndrome – the heart of the matter. 2002 Nephrol Dial Transplant doi: 10.1093/ndt/17.suppl_11.28
Hu F, Willett WC. Optimal diets for prevention of coronary heart disease. 2002 JAMA doi: 10.1001/jama.288.20.2569
Keys A. Coronary heart disease – the global picture. 1975 Atheroscler 22(2):149-192
Postmus I, Deelen J, Sedaghat S, Trompet S, de Craen AJM, Heijmans BT, Franco OH, Hofman A, Dehghan A, Slagboom PE, Westendorp RGJ, Jukema JW. LDL cholesterol still a problem in old age? A Mendelian randomization study. 2015 Int J Epidemiol doi: 10.1093/ije/dyv031