Menstruation 10 months earlier if low on vitamin D – Aug 2011

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Low vitamin D linked to early menstruation - 2011

ANI | Aug 12, 2011
Low vitamin D in young girls may lead to early menstruation, which is a risk factor for a host of health problems for teen girls as well as women later in life, according to a new study.

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.

Early menstruation is a risk factor for behavioural 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.

In the research by Villamor and colleagues, 57 per cent of the girls in the vitamin D-deficient group reached menarche during the study, compared to 23 per cent in the vitamin D-sufficient group.

In terms of age, girls who were low in vitamin D were about 11.8 years old when they started menstruating, compared to the other group at about age 12.6 years old.

This 10-month difference is substantial, Villamor said, because even though 10 months may not seem like a long time, at that age a lot is happening rapidly to a young girl's body.

Does vitamin D affect timing of menarche? March 2013

Nutr Rev. 2013 Mar;71(3):189-93. doi: 10.1111/nure.12015. Epub 2013 Jan 29.
Chew A1, Harris SS.
1Bone Metabolism Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging, 711 Washington Street, Boston, Massachusetts 02111, USA. Anna.Chew@tufts.edu

In a recently published prospective study, Villamor et al. found increased risk of early menarche in vitamin D-deficient girls compared to vitamin D-sufficient girls in Bogota, Columbia. The association was not fully explained by differences in body mass index-for-age z-scores. The mechanism for the association, if real, has not been elucidated, but could potentially involve vitamin D receptor polymorphisms. Early menarche and vitamin D deficiency are both associated with poor health outcomes, and further exploration of their association is important for women's health.

PMID: 23452286
Publisher wants $39 for the PDF

http://www.emaxhealth.com/1275/low-vitamin-d-levels-and-early-menstruation-linked
Early menstruation, which is a risk factor for psychosocial and behavioral problems in teens and diseases such as breast cancer in later life, appears to be linked to low levels of vitamin D. The study’s results could have important implications for young girls around the world.
The age of first menstruation has been declining

In 1901, a report at the proceedings of the 26th meeting of the American Gynecological Society reported that the mean age of first menstruation (menarche) for girls in the United States and Canada was 13.9 or 14 years. Subsequent research reported that the age of menarche has declined to 12.5 years between 1965 and 1985.

According to one of the authors of the new study, Eduardo Villamor, associate professor in the University of Michigan School of Public Health, the age of menarche has been undergoing a slow decline worldwide for years. He suggests there is an environmental cause behind the decline, because the genetics of puberty have not changed.

One of those environmental causes may be low levels of vitamin D. To investigate this idea, a research team measured the blood levels of vitamin D in 242 girls ages 5 to 12 from Bogota, Colombia. All the girls were followed for 30 months.

The investigators found that 57 percent of girls who had low vitamin D levels started menstruation during the study period compared with 23 percent of girls who had sufficient vitamin D levels. Girls who had low vitamin D levels started menarche at about 11.8 years of age, while girls with sufficient vitamin D levels started menstruation at about 12.6 years of age.

Villamor noted that researchers know little about environmental triggers for puberty. “If we learn what is causing the decline in age of first menstruation,” he said, “we may be able to develop interventions” to prevent girls from experiencing premature menarche.

In another recent study, published in Environmental Research, investigators in Taiwan found that women who were exposed to environmental toxins such as polychlorinated biphenyls (PCBs) at age 5 to 9 years started menarche “slightly earlier with borderline significance.” In Reproductive Toxicology, researchers reported they found an association between exposure to DES and early menarche.

The study by Villamor and colleagues is important because it points out a possible link between low vitamin D levels and early menstruation, although it did not establish insufficient vitamin D as a cause of premature menarche. Additional studies are needed to determine if changing girls’ vitamin D levels will cause a change in age of menarche.

SOURCES:
Hatch EE et al. Reproductive Toxicology 2011 Feb; 31(2): 151-57
Medical News 1901 Jun 22; from the proceedings of the 26th meeting of the American Gynecological Society, May 30-June 1, 1901
University of Michigan School of Public Health
Yang CY et al. Environmental Research 2011 Feb; 111(2): 288-94

Low vitamin D may solve mystery of earlier female maturation – and life-long health problems

ProHealth.com http://www.prohealth.com/library/showarticle.cfm?libid=16454
August 11, 2011

If successful, intervention might also reduce the associated life-time risk of behavioral, cardiovascular, and metabolic problems; even breast cancer risk.

A new study links low vitamin D in young girls with early menstruation, which is a risk factor for a host of health problems both during their teens and later in life.

Researchers at 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 nearly 2.5 times as likely to start menstruation during the study than those with sufficient vitamin D, says epidemiologist Eduardo Villamor, MD, MPH, DrPH. [See “Vitamin D deficiency and age at menarche: A prospective study,” American Journal of Clinical Nutrition, Aug 10, 2011.]

This is important for several reasons, says Dr. Villamor. There has been a slow worldwide decline in the age of the first menstruation, or menarche, for years, suggesting it has an environmental cause, since the genetics that trigger puberty haven't changed.

Successful Intervention Might Reduce Lifelong Disease Risk

"We know relatively little about what triggers puberty from an environmental perspective," says Dr. Villamor. "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 cardio-metabolic diseases and cancer - particularly breast cancer, as adults.

Latitude is a Known Factor in Premature Maturation
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 deficiency during winter months because of limited sun exposure.

In the research by Villamor and colleagues:

57% of the girls in the vitamin D-deficient group reached menarche during the study, compared to 23% in the vitamin D-sufficient group.
In terms of age, girls who were low in vitamin D were about 11.8 years old when they started menstruating, compared to the other group at about age 12.6 years old.

This 10-month difference is substantial, Dr. Villamor explains, because even though 10 months may not seem like a long time, at that age a lot is happening rapidly to a young girl's body.

Still, while the results suggest a link between vitamin D and menarche, they have not established a causal relationship. It's necessary to do more studies to show if interventions that change girls' vitamin D status result in a change in their age of menarche.

Source: University of Michigan news release, Aug 10, 2011

Vitamin D deficiency and age at menarche: a prospective study 1,2,3

http://www.ajcn.org/content/early/2011/08/10/ajcn.111.018168.abstract
Eduardo Villamor villamor@umich.edu , Constanza Marin, Mercedes Mora-Plazas, Ana Baylin
Departments of Environmental Health Sciences (EV) and Epidemiology (EV and AB), University of Michigan School of Public Health, Ann Arbor, MI; the Department of Nutrition, National University of Colombia, Bogota, Colombia (CM and MM-P); and the Department of Nutrition, Harvard School of Public Health, Boston, MA (EV).
Received April 14, 2011,; Accepted July 7, 2011.
Supported by the Harvard Clinical Nutrition Research Center (P30-DK040561), the University of Michigan Center for Global Health, and the Secretary of Education of Bogota.

Background: Early menarche is a risk factor for cardiometabolic disease and cancer. Latitude, which influences sun exposure, is inversely related to age at menarche. This association might be related to vitamin D, but to our knowledge it has not been investigated in prospective epidemiologic studies.

Objective: We studied the association between vitamin D status and the occurrence of menarche in a prospective study in girls from Bogota, Colombia.

Design: We measured plasma 25-hydroxyvitamin D 25(OH)D concentrations in a random sample of 242 girls (mean ± SD age: 8.8 ± 1.6 y) and followed them for a median of 30 mo. Girls were asked periodically about the occurrence and date of menarche. Baseline 25(OH)D concentrations were categorized as <50 nmol/L (deficient), ?50 and <75 nmol/L, or ?75 nmol/L (sufficient). The incidence of menarche was compared between groups by using time-to-event analyses.

Results: A total of 57% of girls in the vitamin D–deficient group reached menarche during follow-up compared with 23% of girls in the vitamin D–sufficient group (P-trend = 0.0004). The estimated mean (±SE) ages at menarche in the same groups were 11.8 ± 0.2 y and 12.6 ± 0.2 y, respectively (P = 0.0009). After adjustment for baseline age and BMI-for-age z score in a Cox proportional hazards model, the probability of menarche was twice as high in vitamin D–deficient girls than in girls who were vitamin D–sufficient (HR: 2.05; 95% CI: 1.03, 4.07; P = 0.04). Similar results were obtained in girls aged ?9 y at baseline (HR: 2.39; 95% CI: 1.14, 5.00; P = 0.02).

Conclusion: Vitamin D deficiency is associated with earlier menarche.