Beautiful beaches in Somalia, such as this one in Kismayo, help people lead an active lifestyle that they don't maintain when they immigrate to Canada. (Nasteex Faarax/Associated Press)Some healthy people who immigrate to Canada find their health deteriorating after their arrival — an issue immigrant communities are struggling to understand and address.

"The immigrants when they come here, the first five years they are healthy," said Abdirizak Karod, director of the Somali Centre for Family Services in Ottawa.

"After that, they join the club — the Canadian club: they [are] facing…diabetes, autism, blood pressure, depression and all those things."

Abdirizak Karod, director of the Somali Centre for Family Services in Ottawa, said health problems faced by immigrants in Canada, including diabetes, depression and autism, are virtually unheard of in Somalia. (CBC)Many of those problems are virtually unheard of in Somalia, he said.

The problem isn't limited to the Somali community.

It is well established that immigrants and refugees are healthier than the general Canadian population when they arrive, but their health declines after they start living in Canada, said Dr. Kevin Pottie, co-director of the Immigrant Health Program at the Elisabeth Bruyère Research Institute in Ottawa.

Both Pottie and Karod think changes in diet and exercise habits and vitamin D deficiency may all contribute to those health problems.

Karod said that in Somalia, exercise is a part of everyday life.

"The younger generation, they have so many sports," he said. "We have one of the best beaches in Africa, or maybe the world … The older generation, they walk a lot. That prevents a lot of the diseases that we are facing here in Canada or in Europe."

Fruit is cheap and easily available while fatty and sugary items popular in Canada are not.

Karod is also concerned about the role of vitamin D, which is produced by the human body in the presence of sunlight — something that is far more plentiful closer to the equator. People from countries like Somalia often have darker skin than the Canadian average, which makes it more difficult for them to produce vitamin D.

The vitamin is crucial to maintaining healthy bones, and vitamin D deficiency has also been linked to many other diseases such as schizophrenia and autism that are affecting immigrants from sunnier parts of the world in greater numbers.

Schizophrenia and skin colour

Dozens of studies show that rates of schizophrenia increase as you move away from the equator, said Dennis Kinney, a Harvard University genetics researcher. Kinney and his collaborators analyzed 49 studies for larger patterns and noticed that the increase was most prevalent among people with lower fish consumption, higher infant mortality and darker skin.

Dr. Kevin Pottie said a lack of vitamin D has been associated with a lot of health problems, but diet, a lack of exercise and genetics may also play a role. (CBC)Their results, published in Schizophrenia Bulletin in 2009, are consistent with the hypothesis that vitamin D plays a role, Kinney said.

Some parallel studies in Sweden are looking into the very high rates of autism among Swedish children whose families are from sub-Saharan Africa, he said.

Both schizophrenia and autism are known to have a strong genetic component.

"It turns out that vitamin D plays an important role in the regulation and expression of hundreds of genes in the body," Kinney said. "It's also very important for protecting DNA against damage and then repairing it once it occurs."

He suggested that a shortage of vitamin D could lead to mutations in egg and sperm cells and could interfere in early brain development to boost the risk of autism and schizophrenia.

'That's the risk of saying everything is vitamin D — you could miss other diagnoses.'— Dr. Kevin Pottie

Pottie said vitamin D deficiency has also been linked to other mental illnesses such as depression, as well as breast cancer, colon cancer and heart disease.

"But a lot of the … evidence is really just association," he said. "There could be a lot of other things that are playing a role there … it could be a lack of exercise, diet or genetics."

Immigrants' struggles to find a job, the stress of being separated from their families and social support networks could also have a major impact, Pottie said.

"That's the risk of saying everything is vitamin D — you could miss other diagnoses," he said.

Nevertheless, he does recommend that his darker-skinned patients take a vitamin D supplement.

Somali community pushes sports

Karod acknowledged that immigrant communities such as his need to make people aware of the benefits of taking supplements to boost their vitamin D levels, especially before pregnancy.

About 100 Somali-Canadian children and teenagers in Ottawa are being mentored in sports such as skating and skiing this winter. (CBC)Karod said Ottawa's Somali community is also working to address other factors that could play a role.

When it comes to mental illness, Karod acknowledged that cultural barriers must also be addressed.

"It is taboo in the Somali community that your child has … depression," he said.

It is important to teach parents the symptoms to ensure their children get treatment if they do suffer from mental illness.

"We're understanding now there is issues we have to deal with as a community," Karod said. "Do we need help? Yes, we need help."

The Somali Centre for Family Services is already seeing the fruits of some of its efforts. It runs recreational programs for youth every weekend, encouraging them to exercise by playing basketball and soccer — and even participating in "Canadian sports" like skiing and skating, Karod said.

More than 100 youth are being mentored in those sports this winter.

"And now it's becoming popular," Karod said. "Now, [even] the fathers are starting doing those sports."