Vitamin D non-skeletal health benefits unclear
Posted: May 18, 2012 3:11 PM ET
Last Updated: May 18, 2012 3:08 PM ET
Taking vitamin D supplements for bone health is fine but using it to prevent and treat other diseases doesn't have clear evidence, a panel of medical experts says.
The Endocrine Society, which includes American and Canadian specialists, reviewed the evidence on vitamin D beyond bone health.Research into vitamin D to prevent and treat disease has exploded in recent years. (David Gray/Reuters)
Vitamin D is a steroid hormone that regulates calcium and phosphate levels in the blood and promotes the growth of healthy bones.
"The role of vitamin D supplementation in the prevention and treatment of chronic non-skeletal diseases remains to be determined," Dr. Clifford Rosen of Tufts University School of Medicine and chair of the task force said in a statement Friday.
"We need large randomized controlled trials and dose-response data to test the effects of vitamin D on chronic disease outcomes including autoimmunity, obesity, diabetes, hypertension and heart disease."
Vitamin D deficiency can lead to muscle weakness, osteoporosis and bone softening.
Canadian prevention trial
Before releasing their scientific statement on vitamin D, the society's panel evaluated the literature for each organ system using information from randomized trial experiments and observational studies.
Their conclusions included:
- Vitamin D pills, gels or ointments may be useful in treating skin disorders such as psoriasis but large, placebo-controlled clinical trials are needed to test if it works to prevent or treat skin cancer.
- There's no strong evidence that vitamin D supplementation reduces the risk of Type 2 diabetes or metabolic syndrome, a group of risk factors like high blood pressure, high blood sugar, excess abdominal fat, abnormal cholesterol levels and obesity that occur together.
- The supplements are likely to reduce the risk of falls, especially in those who have low levels and are also taking calcium pills.
- Observational evidence is strongest for vitamin D reducing colorectal cancer but the proof is weak or inconsistent for cancer overall and breast and prostate tumours.
- There's not enough evidence from clinical trials to support taking vitamin D to lower cardiovascular disease risk.
Clinical trials are also needed to test whether giving vitamin D supplements in pregnancy will prevent Type 1 diabetes after birth. Dr. Shayne Taback, a pediatric endocrinologist in Winnipeg, is scheduled to find out next month whether a Canadian clinical trial will be funded.
Research investigating vitamin D was aided by the discovery of its receptor in 1987.
"Its subsequent identification in virtually all tissues spurred further basic and clinical studies and led to a much greater appreciation of the physiological role of vitamin D," the group wrote.
"At the same time, interest in vitamin D as a therapeutic modality for the prevention of chronic diseases grew exponentially. Indeed, in a two-month span during the summer of 2011, there were more than 500 publications centered on vitamin D, most of which [involved] its relationship to nonskeletal tissues."
In 2010, the Institute of Medicine, an independent organization that advises the U.S. and Canadian governments, concluded most people are getting enough of the vitamin.
The new statement was published in Endocrine Reviews.
Top News Headlines
- 3 more suspects arrested in slaying of U.K. soldier
- British police investigating the savage killing of an off-duty soldier in London have arrested three more suspects. more »
- Hockey Canada votes to ban bodychecking in peewee hockey
- Hockey Canada's board of directors voted to eliminate bodychecking from peewee-level hockey on Saturday in Charlottetown. more »
- Neil Macdonald: How serious is Obama about curbing the drone surge?
- In a key speech this week, the U.S. president set out a host of supposed new safeguards for America's controversial practice of remote-controlled rough justice. But as Neil Macdonald writes, the underlying rationale for drone use has not fundamentally changed. more »
- Ontario man lost in Australian mountains has survival skills
- The sister of an Ontario man who disappeared in Australia's Snowy Mountains nearly two weeks ago says she remains hopeful he will be found, partly because of his training as a Canadian Forces reservist. more »
Latest Health News Headlines
- WHO to help Saudi Arabia's coronavirus investigation before hajj
- The World Health Organization plans to help Saudi Arabia dig deeper into deadly outbreaks of a new coronavirus to draw up advice ahead of the annual hajj pilgrimage, which attracts millions of Muslims. more »
- Protesters march against GMO giant Monsanto in 430 cities
- Marches and rallies against seed giant Monsanto were held across Canada, the U.S. and in dozens of other countries Saturday. more »
- Coroner's jury recommends pool safety changes
- The jury of a coroner's inquest into the drowning of a Chinese student in Saint John is calling for province-wide safety standards at all public pools and increased minimum training for paramedics. more »
- New blood restrictions still discriminate against gay men, advocates say
- Health Canada has loosened decades-old restrictions on gay men giving blood — but it's still not nearly enough, Hamilton advocates say. more »
- McDonald's CEO chastised by 9-year-old B.C. girl
- Will Rob Ford's supporters leave Ford Nation?
- Toronto mayor's brother says he never dealt drugs
- Toronto Mayor Rob Ford denies using crack cocaine
- Dog snared on baited hooks near Vancouver's Grouse Grind trail
- 3 more suspects arrested in slaying of U.K. soldier
- Washington police blame bridge collapse on Alberta trucker
- Wallin may be forced to repay thousands in travel expenses
- Canada ranks 3rd last in paid vacations