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Winter vitamin D deficiency could lead to depression

By Michelle Poirier [1]

BELLEVILLE – Some students at Loyalist College may be facing the winter blues, which new studies show can be due to a lack of vitamin D.

When those blues are really bad, it could be something called seasonal affective disorder.

Lauren Deans, registered nurse at Loyalist College, explained how someone affected with SAD may feel.

“You just don’t feel happy. You know, you’re not suicidal or anything, but you’re just not happy. Things just don’t feel right. And there are some people who they even need to go on antidepressants for the winter. And then once the days get longer they perk up and they can stop taking them,” she said.

MedlinePlus [2], associated with the U.S. National Institutes of Health [3], says that not everyone with SAD has the same symptoms. SAD is a type of depression that usually affects people during the winter months. The symptoms include:

“I would say that there’s probably a quarter of the students affected by it, but very few know it,” Deans said.

A new study [4] from the University of Georgia, the University of Pittsburgh and the Queensland University of Technology links SAD with low levels of vitamin D. They show that vitamin D is involved in the synthesis of serotonin and dopamine in the brain. According to researchers, a shortage of these chemicals is linked to depression, which means there may be a link between low levels of vitamin D and depression.

According to the Vitamin D Society [5], humans make 90 per cent of their vitamin D through ultraviolet B rays from exposure to the sun. In Canada, for four to six months of the year the UVB levels in sunlight are too weak to make vitamin D naturally.

In an email to QNet News, Perry Holman, executive director of the Vitamin D Society, explained that the average level of vitamin D in Canadians declined by 6.2 per cent between 2007 and 2009, when national studies were carried out. The 2009 study found that 32 per cent of Canadians, or 11 million people, had blood concentrations of vitamin D below the minimum level set by Health Canada [6] and the Institute of Medicine [7]. This statistic gets worse in the winter; it rises to 40 per cent of Canadians with insufficient levels of vitamin D, with 10 per cent of those being severely deficient.

“Being a Canadian, we should all be taking vitamin D on a regular basis,” Deans said. “Because we’re just that far away from the equator that we need to take extra vitamin D.”

Vitamin D can also be found in some foods, according to Dieticians of Canada [8]. It is found naturally in egg yolks, salmon, mackerel, sardines and tuna, while it is added in cow’s milk, infant formula and margarine, which the Canadian government requires. It can also be added in some yogurts, cheese, plant-based beverages and orange juice.

MedlinePlus says nearly half of people affected by SAD need antidepressants and talk therapy to help them feel better. However, for some people ulrtaviolet light therapy can also be very effective.

Loyalist College now has two SAD light boxes; you sit under the light for about 20 minutes every so often (depending on what the nurse says) and you may start to feel better. The lights are not like tanning beds; they are like sunlight, Deans said. Loyalist also provides counselling services [9] for students who require it.

“We have about a dozen people who use the lamps regularly,” Deans said.

If you think you are dealing with SAD, Deans suggests you check with a health professional.

“There are lots of other reasons why you could feel down – like your thyroid could be out of whack, hemoglobin out of whack, stuff like that. So you know you’ve got to rule out the physicality things and then you start looking at the mental/emotional,” Deans said.