Vitamin D: all the benefits

There is a relationship between health status and vitamin D. When it is found in the blood in optimal concentrations, it is associated with a substantial decrease in the risk of cardiovascular and respiratory diseases, bone fractures, and mortality.

This is according to a study published in the American Journal of Clinical Nutrition and conducted by researchers at the School of Clinical Medicine, University of Cambridge, Great Britain, who examined the relationship between serum vitamin D levels and the incidence of disease and mortality in adults.

The sunshine vitamin

The term vitamin D refers to two biologically inactive precursors: D3, also known as cholecalciferol, and D2 known as ergocalciferol. Both D3 and D2 are converted in the liver and kidneys into 25-hydroxyvitamin D (25(OH)D), the storage form of the vitamin, and 1,25-dihydroxyvitamin D (1,25(OH)2D) the active form. As is well known, in addition to taking in vitamin D from food, the human body can produce it through a series of reactions that begin with the action of sunlight on the skin. Therefore, in some countries, especially during the winter months, vitamin D deficiency is very common, in which case dietary supplements and fortified foods can help increase the 'intake.

In optimal amounts it reduces the risk of disease

The researchers, led by Kaytee Khaw, collected, between 1997 and 2000, data on serum vitamin D concentrations in 14,641 men and women, aged 42 to 82 years, living in Norfolk, UK. The participants, who were followed until 2012, were divided into 5 groups based on serum concentrations of 25(OH) D. Taking into account variables such as age, sex, smoking, and physical activity, the results showed that for each 20nmol/L increase in 25(OH) D concentration, the risk of cardiovascular disease was decreased by 4 percent, respiratory disease by 11 percent, fractures by 11 percent, and mortality by 8 percent. Notably, the highest mortality rates were observed in individuals with concentrations below 30 nmol/L, while the lowest mortality rates were found in individuals with concentrations above 90 nmol/L . However, unlike other studies, no association was found between vitamin D levels and cancer risk.

Vitamin D supplementation to reduce deficiency

The results of the study showed that there was a significant reduction in the risk of respiratory disease, bone fracture and cardiovascular disease in subjects with high vitamin D levels. The risk of mortality also appeared lower in adults with concentrations greater than 90 nmol/L , and there was no evidence of increased mortality for subjects in the group with higher concentrations, suggesting that a moderate increase in concentrations may have potential health benefits without harmful effects. 

 Source: KT. Khaw, R. Luben, N. Wareham. "Serum 25hydroxyvitamin D, mortality, and incident cardiovascular disease, respiratory disease, cancers, and fractures: a 13y prospective population study "American Journal of Clinical Nutrition . Published online ahead of print, doi: 10.3945/ ajcn.114.086413