According to a new study led by Dr Diana van Heemst of the Leiden University Medical Center, the Netherlands, low levels of vitamin D may be associated with familial longevity.
“We found that familial longevity was associated with lower levels of vitamin D and a lower frequency of allelic variation in the CYP2R1 gene, which was associated with higher levels of vitamin D,” Dr van Heemst and her team said in a paper published in the Canadian Medical Association Journal.
Previous works have shown that low levels of vitamin D are associated with increased rates of death, heart disease, diabetes, cancer, allergies, mental illness and other afflictions. However, it is not known whether low levels are the cause of these diseases or if they are a consequence.
The team looked at data from 380 white families with at least 2 siblings over age 90 in the Leiden Longevity Study to determine whether there was an association between vitamin D levels and longevity. The study involved the siblings, their offspring and their offsprings’ partners for a total of 1038 offspring and 461 controls. The children of the nonagenarians were included because it is difficult to include controls for the older age group.
The researchers measured levels of 25-hydroxyvitamin D, a prehormone that is produced in the liver by hydroxylation of vitamin D, and categorized levels by month as they varied according to season. The researchers controlled for age, sex, body mass index, time of year, vitamin supplementation and kidney function, all factors that can influence vitamin D levels. They also looked at the influence of genetic variation in 3 genes associated with vitamin D levels.
“We found that the offspring of nonagenarians who had at least 1 nonagenarian sibling had lower levels of vitamin D than controls, independent of possible confounding factors and single nucleotide polymorphisms associated with vitamin D levels,” the team said. “We also found that the offspring had a lower frequency of common genetic variants in the CYP2R1 gene; a common genetic variant of this gene predisposes people to high vitamin D levels.”
“The findings support an association between low vitamin D levels and familial longevity,” the researchers concluded.
Bibliographic information: Raymond Noordam et al. Levels of 25-hydroxyvitamin D in familial longevity: the Leiden Longevity Study. CMAJ, first published online November 5, 2012; doi: 10.1503/cmaj.120233