Low vitamin D levels may increase death risk in patients with hypertension

According to a new US study a low dietary vitamin D intake in mid-life seems to be linked to a higher total mortality among hypertensive subjects.

The cohort study used food questionnaires to estimate the intakes of vitamin D of 8006 Japanese American men aged 45 to 68 and documented cases of death during 45 years (1). The study results showed that among participants with hypertension those with the highest vitamin D intakes were significantly less likely
to die than those with the lowest intakes.

The researchers commented that vitamin D may have heart protective effects which support health in gene- ral. They noted that the used calculations of nutrient intake were crude estimates of vitamin D status based on food questionnaires. As people in general are not very good at recording what and how much they eat, vitamin concentrations in blood, tissue or urine are the most accurate reflection of the nutritional status. An earlier meta-analysis of 12 studies reported a 20 nmol/L increase in blood serum vitamin D3 concentrations was associated with an 8% decrease in all-cause mortality (2).

1. Kojima G. et al. Low dietary vitamin D in mid-life predicts total mortality in men with hypertension: The Honolulu Heart Program. J Am Coll Nutr. Published online April 2014.
   
2. Schottker B. et al. Serum 25-hydroxyvitamin D levels and all mortality. A systematic review and meta-analysis of prospective cohort studies. Ageing Res Rev. 2013; 12(2):708-718.