Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Vitamin D levels have different effects on atherosclerosis in blacks and whites

15.03.2010
Vitamin D is quickly becoming the "go-to" remedy for treating a wide range of illnesses, from osteoporosis to atherosclerosis. However, new evidence from a Wake Forest University School of Medicine study suggests that supplementing vitamin D in those with low levels may have different effects based on patient race and, in black individuals, the supplement could actually do harm.

The study is the first to show a positive relationship between calcified plaque in large arteries, a measure of atherosclerosis or "hardening of the arteries," and circulating vitamin D levels in black patients. It appears in the March issue of the Journal of Clinical Endocrinology and Metabolism.

"In black patients, lower levels of vitamin D may not signify deficiency to the same extent as in whites," said the study's lead investigator, Barry I. Freedman, M.D., John H. Felts III Professor and chief of the section on nephrology at the School of Medicine "We should use caution when supplementing vitamin D in black patients while we investigate if we are actually worsening calcium deposition in the arteries with treatment."

Vitamin D is widely used to treat patients with osteoporosis and/or low vitamin D levels based on a medically accepted normal range. This "normal" range is typically applied to all race groups, although it was established predominantly in whites. It is thought that as low vitamin D levels rise to the normal range with supplementation, protection from bone and heart disease (atherosclerosis) may increase, as well.

Blacks generally have lower vitamin D levels than whites, partly because their darker skin pigmentation limits the amount of the vitamin produced by sunlight. Blacks also consume fewer dairy products and ingest less dietary calcium than whites, said Freedman, an affiliate of the Maya Angelou Center for Health Equity, part of the School of Medicine. Despite these lower vitamin D levels and dietary calcium ingestion, blacks naturally experience lower rates of osteoporosis and have far less calcium in their arteries. Studies further reveal that black patients with diabetes have half the rate of heart attack as whites, when provided equal access to health care. This shows that lower levels of calcified atherosclerotic plaque in blacks are associated with a lower risk of heart disease. However, blacks in the general community have higher rates of heart attack than whites, potentially due to unequal access to medical care, Freedman said.

The research team determined the relationship between circulating vitamin D levels and arterial calcium in 340 black men and women with type 2 diabetes. Calcium can deposit in blood vessel walls forming a bone-like material called "calcified atherosclerotic plaque" and this plaque can be detected by computed tomography (CT) scans. Calcified atherosclerotic plaque is a reliable predictor of risk for heart attack and stroke. The investigators measured vitamin D levels in all study participants and then performed a CT scan to detect calcium in the heart and major arteries.

"We found that higher circulating levels of vitamin D in blacks were associated with more calcium in the artery walls," Freedman said. "This is the opposite effect of what is felt to occur in white patients and shows that the accepted "normal" range of vitamin D may be different between blacks and whites.

"Many of these study patients would be placed on supplemental vitamin D by their physicians simply because their levels were felt to be in the low range." Freedman added that physicians should use caution in supplementing vitamin D levels in blacks – especially if they do not have weak bones or other reasons to take this vitamin – until the effects of supplementing vitamin D on blood vessels and heart disease are better understood.

"Doctors frequently prescribe supplemental vitamin D," Freedman said. "However, we do not know all of its effects and how they may differ between the races. The bottom line is that racial differences in calcium handling are seen and black and white patients have differing risk for bone and heart disease. We should more clearly determine the effects of supplementing vitamin D in black patients with low levels based on existing criteria and should not assume that the effects of supplementation will be the same between the races."

Co-authors of the study, which was funded by the National Institutes of Health, were Lynne E. Wagenknecht, Dr.P.H., Kristen G. Hairston, M.D., Donald W. Bowden, Ph.D., J. Jeffrey Carr, M.D., R. Caresse Hightower, Ethel J. Gordon, Jianzhao Xu, Carl D. Langefeld, Ph.D., and Jasmin Divers, Ph.D., all of the School of Medicine.

Media Relations Contacts: Jessica Guenzel, jguenzel@wfubmc.edu, (336) 716-3487; or Bonnie Davis, bdavis@wfubmc.edu, (336) 716-4977.

Wake Forest University Baptist Medical Center (www.wfubmc.edu) is an academic health system comprised of North Carolina Baptist Hospital, Brenner Children's Hospital, Wake Forest University Physicians, and Wake Forest University Health Sciences, which operates the university's School of Medicine and Piedmont Triad Research Park. The system comprises 1,056 acute care, rehabilitation and long-term care beds and has been ranked as one of "America's Best Hospitals" by U.S. News & World Report since 1993. Wake Forest Baptist is ranked 32nd in the nation by America's Top Doctors for the number of its doctors considered best by their peers. The institution ranks in the top third in funding by the National Institutes of Health and fourth in the Southeast in revenues from its licensed intellectual property.

Jessica Guenzel | EurekAlert!
Further information:
http://www.wfubmc.edu

More articles from Studies and Analyses:

nachricht WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

nachricht First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

When corals eat plastics

24.05.2018 | Ecology, The Environment and Conservation

Surgery involving ultrasound energy found to treat high blood pressure

24.05.2018 | Medical Engineering

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>