Vitamin D deficiency is associated with multiple serious health conditions as we get older. Free, circulating vitamin D levels in the bloodstream is a more accurate predictor of future health and disease risk than the often measured total vitamin D, according to a new study.
Getting enough, but not too much, vitamin D is needed to keep the body functioning well. Vitamin D deficiency is common in Europe, especially in elderly people, and has been associated with a higher risk for developing diseases such as osteoporosis, cardiovascular disease, and cancer.
There are several forms of vitamin D in the body. currently, the total amount of these forms are the most often used to assess the vitamin D status in the human body. More than 99% of all vitamin D forms in our blood are bound to proteins. Only a very small fraction is free to be biologically active. Therefore these free, active forms, maybe a better predictor of current and future health.
Vitamin D is the only nutrient your body produces when exposed to sunlight.
Up to 50 percent of the world’s population may not get enough sun, and 40 percent of U.S. residents are vitamin D deficient
The recommended daily value (DV) is 800 IU (20 mcg) of vitamin D per day from food
Healthy foods high in vitamin D are:
Fish – Salmon, Herring, Sardins, Cod liver oil, canned Tuna
Whole eggs – mostly in the yolk, Mushrooms, Cow’s milk, Soy milk, Orange juice, Cereal and oatmeal
Using data from the European Male Ageing Study, collected from 1,970 men, aged 40-79, between 2003 and 2005, Dr. Leen Antonio from University Hospitals Leuven in Belgium and his team investigated whether the free metabolites of vitamin D were better health predictors.
The levels of total and free metabolites of vitamin D were compared with their current health situation, adjusting for potentially confounding factors, including age, smoking, body mass index, and self-reported health.
The prohormone 25-dihydroxyvitamin D is converted to 1,25-dihydroxyvitamin D, which is considered the active form of vitamin D in the body.
only free 25-hydroxyvitamin D was predictive of future health problems and not free 1,25-dihydroxyvitamin D.
The total levels of both free and bound vitamin D metabolites were associated with a higher risk of death.
Dr Antonio explains, “These data further confirm that vitamin D deficiency is associated with a negative impact on general health and can be predictive of a higher risk of death.”
As this is an observational study, the causal relationships and underlying mechanisms remain undetermined. It was also not possible to obtain specific information about the causes of death of the men in the study, which may be a confounding factor.
“Our data now suggest that both total and free 25-hydroxyvitamin D levels are the better measures of future health risk in men,” says Dr Antonio