Monday, March 24, 2014

Under new guidelines, only 10 percent of children at risk of low vitamin D levels, Loyola study finds

MAYWOOD, Ill. – Under new guidelines from the Institute of Medicine, the estimated number of children who are at risk of having insufficient or deficient levels of vitamin D is drastically reduced from previous estimates, according to a Loyola University Chicago Stritch School of Medicine study.

The study, led by Holly Kramer, MD, MPH, and Ramon Durazo-Arvizu, PhD, is published online ahead of print in the Journal of Pediatric Endocrinology and Metabolism.

New Institute of Medicine guidelines say most people get sufficient vitamin D when their blood levels are at or above 20 nanograms per milliliter (ng/mL). The Pediatric Endocrine Society has a similar guideline. However, other guidelines recommend vitamin D levels above 30 ng/mL.

Loyola researchers studied vitamin D data from a nationally representative sample of 2,877 U.S. children and adolescents ages 6 to 18 who participated in the National Health and Nutrition Examination Survey.

The study found that under the Institute of Medicine guidelines, 10.3 percent of children ages 6 to 18 are at risk of inadequate or deficient vitamin D levels. (This translates to an estimated 5.5 million children.)

By comparison, a 2009 study in the journal Pediatrics, which defined sufficient vitamin D levels as greater than 30 ng/mL, found that an estimated 70 percent of people ages 1 to 21 had deficient or insufficient vitamin D levels.

Under previous guidelines, millions of children who had vitamin D levels between 20 and 30 ng/mL would have needed supplementation. Under the Institute of Medicine guidelines, children in this range no longer need to take vitamin D supplements.

The new study found that children at risk of vitamin D deficiency under the Institute of Medicine guidelines are more likely to be overweight, female, non-white and between the ages of 14 and 18.

The Institute of Medicine’s new vitamin D guidelines are based on nearly 1,000 published studies and testimony from scientists and other experts. The IOM found that vitamin D is essential to avoid poor bone health, such as rickets. But there have been conflicting and mixed results in studies on whether vitamin D can also protect against cancer, heart disease, autoimmune diseases and diabetes. Moreover, excessive vitamin D can damage the kidneys and heart, the IOM found.

The Loyola study is titled “Prevalence of risk of deficiency and inadequacy of 25-hydroxyvitamin D in U.S. Children: NHANES 2003-2006."

Authors of the Loyola study work in the departments of Public Health Sciences and Pediatrics. In addition to Kramer and Durazo-Arvizu, they are Vytas P. Karalius, MPH, MA (first author); Daniel Zinn, MD; James Wu, MD; Guichan Cao, PhD; Carla Minutti, MD; and Amy Luke, PhD.

About Loyola University Health System

Loyola University Health System (LUHS) is part of Trinity Health. Based in the western suburbs of Chicago, LUHS is a quaternary care system with a 61-acre main medical center campus, the 36-acre Gottlieb Memorial Hospital campus and more than 30 primary and specialty care facilities in Cook, Will and DuPage counties. Loyola University Medical Center’s campus is conveniently located in Maywood, 13 miles west of Chicago’s Loop and 8 miles east of Oak Brook, Ill. At the heart of the medical center campus is a 559-licensed-bed hospital that houses a Level 1 Trauma Center, a Burn Center and the Ronald McDonald® Children's Hospital of Loyola University Medical Center. Also on campus are the Cardinal Bernardin Cancer Center, Loyola Outpatient Center, Center for Heart & Vascular Medicine and Loyola Oral Health Center as well as Loyola University Chicago Stritch School of Medicine, Loyola University Chicago Marcella Niehoff School of Nursing and the Loyola Center for Fitness. Loyola's Gottlieb campus in Melrose Park includes the 255-licensed-bed community hospital, the Professional Office Building housing 150 private practice clinics, the Adult Day Care, the Gottlieb Center for Fitness, Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park.

Trinity Health is a national Catholic health system with an enduring legacy and a steadfast mission to be a transforming and healing presence within the communities we serve. Trinity is committed to being a people-centered health care system that enables better health, better care and lower costs. Trinity Health has 88 hospitals and hundreds of continuing care facilities, home care agencies and outpatient centers in 21 states and 119,000 employees.