(RxWiki News) Vitamin D is an important nutrient that people get through their diet and that the body produces when exposed to sunlight. If people do not have enough of the vitamin in their blood, they might be at risk for some serious health problems.
A recent review of studies found that people with low levels of vitamin D in their blood were at increased risk for death from any cause, as well as from heart disease.
The researchers discovered that low concentrations of vitamin D increased the risk of dying from cancer only among people with a history of cancer, suggesting that low vitamin D levels might predict cancer outcome.
"Ask a nutritionist how to maintain healthy levels of vitamin D."
The lead author of this review was Ben Schöttker, a postdoctoral scientist from the Division of Clinical Epidemiology and Aging Research at the German Cancer Research Center in Heidelberg, Germany.
The review included eight previously published studies on the association between vitamin D concentration in the blood and risk of death.
In total, the studies included 26,018 men and women, aged 50 to 79 years old, from 16 European countries and the United States. Follow-up periods ranged from four years to 16 years.
The findings showed that vitamin D concentrations varied with season, country and sex, but not with age.
Vitamin D concentrations were the highest during the summer, in the United States and Northern Europe, and in men.
After a total follow-up of 16 years, the researchers found that 6,695 participants had died. Among them, 2,624 died from heart disease and 2,227 died from cancer.
The researchers split up participants into five groups according to levels of vitamin D.
The participants with the lowest vitamin D concentrations had a 57 percent increased risk of dying from any cause compared to the participants with the highest vitamin D concentrations.
Among the participants who did not have a history of heart disease, those with the lowest levels of vitamin D in their blood had a 41 percent increased risk of death from heart disease compared to those with the highest levels of vitamin D in their blood.
Similarly, the participants who did have a history of heart disease and had the lowest vitamin D concentrations were 65 percent more likely to die from heart disease than the participants with a history of heart disease and the highest amount of vitamin D in their blood.
Among the participants with a history of cancer, those with the lowest levels of vitamin D were 70 percent more likely to die from cancer than those with the highest levels of vitamin D in their blood.
The participants who did not have a history of cancer did not have a significantly increased risk of death due to cancer according to vitamin D levels.
According to the researchers, these findings show that vitamin D may have an important role in predicting cancer outcomes. However, they also said that they could not rule out the possibility that the participants’ cancer may have led to low levels of vitamin D.
Schöttker and team also recommended that all-cause death due to low levels of vitamin D should be made a public health priority.
These researchers concluded that the participants with the lowest levels of vitamin D were at increased risk of death from any cause, from heart disease and from cancer (only among those who had a history of cancer). In addition, the researchers noted that these associations were consistent across seasons, countries, sexes and age groups.
This research was limited because the data were recorded at one point in time, so the researchers could not determine a cause-and-effect relationship.
This review was published on June 17 in BMJ.