August 12, 2011
A study conducted by the University of Michigan School of Public Health found that Colombian girls 5 to 12 years old with low vitamin D levels doubled their chance of having their first period, called menarche, during the 30 month follow up. Fifty-seven percent of deficient girls reached menarche around 11.8 years compared to 12.6 years in the sufficient group. Only 23 percent of girls with normal vitamin D had their first period during the study. Early menstruation is linked to behavioral and social problems in teenagers and increases the risk of developing cardiometabolic diseases and breast cancer in adulthood. Previous research has shown that girls closer to the Equator reach menarche later than girls in northern regions where vitamin D deficiency is common in the winter.
(Aug. 12, 2011) — A study links low vitamin D in young girls with early menstruation, which is a risk factor for a host of health problems for teen girls as well as women later in life.
Researchers from the University of Michigan School of Public Health measured the blood vitamin D levels in 242 girls ages 5-12 from Bogota, Colombia, and followed them for 30 months. Girls low on vitamin D were twice as likely to start menstruation during the study than those with sufficient vitamin D, said epidemiologist Eduardo Villamor, associate professor in the U-M SPH.
This is important for several reasons, Villamor said. Worldwide, there has been a slow decline in the age of the first menstruation, or menarche, for years, which Villamor says suggests an environmental cause, since the genetics that trigger puberty haven’t changed.
“We know relatively little about what triggers puberty from an environmental perspective,” Villamor said. “If we learn what is causing the decline in age of first menstruation, we may be able to develop interventions” to prevent premature menarche.
Early menstruation is a risk factor for behavioral and psychosocial problems in teens. Also, girls who have an earlier menarche appear to have increased risk of developing cardiometabolic diseases and cancer — particularly breast cancer, as adults.
This study formally explored the link between vitamin D status of girls and the time of their first menstruation. Previous research has suggested that menarche happens later in girls living closer to the Equator than girls living in northern countries. Coincidentally, girls in northern countries may harbor high rates of vitamin D deficiencyduring winter months because of limited sun exposure.