Decreased levels of vitamin D associated with reduced methylation in African American teens – ProHealth
April 27 2016. An article that appeared on December 2, 2015 in the journal PLOS One reports reduced levels of methylation and vitamin D in teenaged African Americans, among whom vitamin D deficiency is a common concern. Low levels of methylation are associated with a number of cancers and other conditions, as are decreased levels of vitamin D.
“Methylation is kind of like a brake that controls gene expression,” explained senior author Yanbin Dong who is a geneticist and cardiologist at the Medical College of Georgia at Augusta University. “If that brake is removed or damaged, the gene can go in all kinds of directions, and most of the time, it’s unfavorable ones.”
The study included 454 teens aged 14 to 18 years. While 99% of Caucasian participants had adequate 25-hydroxyvitamin D levels, deficiencies were found among 66% of African American subjects, all of whom had lower levels of global methylation than the Caucasian participants.
When monthly doses of 18,000 international units (IU), 60,000 IU, or 120,000 IU vitamin D3 or a placebo were evaluated in 58 deficient African American teens with low methylation levels, methylation activity increased in association with higher doses of the vitamin.
“This is the first evidence associating low vitamin D levels with hypomethylation,” Dr Dong announced. “If you don’t have enough vitamin D, you don’t have enough methylation.”
“While much work remains, there appears to be a connection between healthy vitamin D levels and levels of DNA methylation,” noted first author Haidong Zhu, who is a molecular geneticist at the Georgia Prevention Institute at the Medical College of Georgia. “We want to understand underlying mechanisms for how vitamin D insufficiency causes cancer, cardiovascular disease and immune system problems.”