A new review out of London, England is shedding light on the benefits of taking vitamin D, or the “sunshine vitamin” as its commonly called. The findings, published in the Cochrane Library by researchers at Queen Mary University on Sept. 5, suggest that taking vitamin D supplements can help reduce the risk of severe asthma attacks by half.

Researchers looked at nine randomized clinical trials involving nearly 1,100 patients for up to a year. Seven of the trials included 435 children and two other trials involved 658 adults. They found that giving their subjects vitamin D supplements along with their regular medication cut the risk of severe asthma attacks requiring hospitalization from six per cent to three per cent. The studies also showed that the supplementation reduced the need for treatment using steroid tablets.

According to the Asthma Society of Canada, more than three million Canadians have asthma and approximately 250 die from the condition every year. Dr. Orli Goldberg, a family physician at the Forest Hill Family Health Centre, explained on CTV’s Your Morning on Tuesday, that vitamin D is so beneficial for asthma sufferers and for other medical conditions because of its anti-inflammatory properties.

“Vitamin D helps reduce the inflammation in the lungs (of asthma patients) and it also helps ward off infections that can trigger asthma attacks,” she said.

Goldberg stressed that the results from this study are only related to serious asthma attacks and that vitamin D supplements may not be useful in the treatment of day-to-day symptoms.

Multiple Sclerosis (MS):

The benefits of vitamin D aren’t limited to the treatment of asthma. Goldberg says that taking vitamin D supplements may also be helpful in preventing osteoporosis, cancer, heart disease, dementia and multiple sclerosis. Canada has the highest rate of MS in the world with an estimated 100,000 Canadians living with the degenerative disease, according to the Multiple Sclerosis Society of Canada. Goldberg believes the high prevalence is due in part to the lack of sunshine most Canadians receive given the country’s distance from the equator.

“We only have about three to four months of intense sunshine a year,” she said.

Similar to asthma, MS also involves inflammation in the body. Goldberg says there have been a number of studies that show that low levels of vitamin D in the blood can lead to the development of MS. She also says that MS can be a more intense disease for patients who have already been diagnosed and don’t have enough vitamin D in their blood.

Can you have too much of a good thing?

Goldberg warns that vitamin D is fat-soluble instead of water-soluble like most vitamins. She says it’s harder for the body to rid itself of vitamin D because excess amounts are stored in fat cells. Excess quantities of water-soluble vitamins, such as vitamin C, are easier to dispose of by urinating.

“If you do take excess amounts (of vitamin D) you can actually get vitamin D toxicity which would cause extra calcium buildup in your blood,” she said.

Extra calcium in the blood could cause poor appetite, nausea, vomiting, weakness, frequent urination or kidney problems according to Goldberg.

How much should you take?

Besides sunlight, vitamin D can be found in limited amounts in foods such as eggs, cereals and fatty fish. However, the majority of vitamin D that the body absorbs comes from sunlight, so Goldberg recommends Canadians take daily vitamin D supplements to offset the lack of sunshine during the darker months. Goldberg recommends Canadians take the following amounts of vitamin D per day.

Infants:

Infants should be given 400 IU (international units) of vitamin D per day starting from birth.

Healthy young adults:

They should take 400 to 1,000 IU daily.

50 years old or over:

Older adults should take 800 to 2,000 IU daily.

High-risk individuals:

Anyone with a high-risk for developing a deficiency, such as those who spend a lot of time indoors, have darker skin tones or who have malabsorption syndrome should also take 800 to 2,000 IU daily.