Nov 2 is Vitamin D Day – Why is that important and what is Trinity doing ?

Posted on: 01 November 2017

Vitamin D Day is a day to recognise vitamin D deficiency as a world problem. Researchers agree that at least one third of the world is deficient in vitamin D, and some scientists even think a greater percent of people are deficient in vitamin D.

Vitamin D has been linked with bone health, muscle function and immune health but doctors are also beginning to discover that vitamin D deficiency is a risk factor for many diseases, including heart disease and cancer.

Furthermore, they’re discovering that vitamin D deficiency may make some diseases more severe, like respiratory diseases and autoimmune diseases like multiple sclerosis and lupus. And they’re discovering that vitamin D can be an important piece in the treatment of some illnesses and diseases, including multiple sclerosis, cystic fibrosis, asthma and many other diseases.

Why are so many people deficient, you might ask? One reason is that we get vitamin D from sun exposure, and now, more than ever, the world’s population lives an indoor lifestyle, avoiding the sun daily.

In Ireland, most vitamin D is synthesised in our skin between March and September. During the Winter months, our body predominantly uses our stores of vitamin D in our bodies, built up in the Summer and Autumn months. To maintain a good level of Vitamin D in our system during this period we need to top up our stores of Vitamin D with vitamin D rich foods (oily fish, liver, mushrooms, fortified foods) and vitamin D supplements. Lots of research has shown that supplementation is very effective in reducing deficiency, especially during winter months at high latitudes.

So what is Trinity College Dublin doing about this world problem of vitamin D deficiency?

In the last year, scientists from the School of Medicine in Trinity developed a vitamin D map of Dublin and found that vitamin D levels were lowest in the most socio-economically deprived and ethnically diverse urban locations including Dublin 8 and Lucan. They also found that levels were lower among younger adults and men.

The Irish Longitudinal Study on Ageing at Trinity found that 1 in 8 older Irish adults are deficient in vitamin D with rates higher in those who were obese, smoked, live in the North West and with a lower asset wealth.

Our scientists also discovered that, contrary to what we might think, sun exposure is an important source of vitamin D in older individuals in Ireland, despite our high latitude. In fact, participants in the study aged 60-74 years who reported enjoying sunshine managed to avoid vitamin D deficiency altogether, even if they were not taking supplements.

Finally, Trinity researchers conducted a review of many studies examining almost 45,000 cancer cases and demonstrated a beneficial role of vitamin D in cancer survival.

Not ones to rest on their laurels, however, the researchers at Trinity are also working on a number of other important vitamin D studies which should be published in the coming months:

They are conducting research looking at vitamin D in pregnancy and vitamin D in ethnic groups. Another study is examining vitamin D and blood pressure and bone health in older adults, while yet another Trinity led study will look at the role of sunshine and vitamin D on the risk and survival of oesophageal and gastric cancer.

Elsewhere in the global research community a research study with 25,874 men and women across the US is investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids reduces the risk for developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses.

Dr Lina Zgaga, Associate Professor of Epidemiology in Trinity said: “Vitamin D deficiency is already strongly linked with many serious conditions, and is suspected to have a role in many more. We already have evidence that suggests the overall health of the Irish population would improve if we tackled vitamin D deficiency. Upcoming studies that will reveal whether that benefit is even greater than we currently believe.”

Dr Zgaga concluded: “For now, people wishing to improve their vitamin D status can go a long way by taking supplements, eating foods rich in vitamin D and spending a little extra time outdoors.”