The sunshine vitamin in Ireland's winter

Most people have heard of vitamin D, or the 'Sunshine Vitamin' as it's sometimes known. Bearing in mind Ireland's typical climate, how do we know we are getting enough when the cold, dark, dreary, miserable (ok you get the picture) winter sets in?

Firstly, what is vitamin D and why is it important?

It is a hormone which mainly controls calcium absorption in the body. This is vital for healthy bones, teeth, and muscle function. Vitamin D status has also been shown to have a link with the development of cancers, multiple sclerosis, cardiovascular health, and diabetes mellitus. Therefore it is important for all around health of the body. For many years, deficiency was rare and it was elderly people (housebound/institutionalised) with low sunlight exposure, or those who observed religious customs like wearing completely covered clothing, who were most at risk. But recent evidence shows a rise in deficiency diseases in developed countries.

Where do we get it from?

Vitamin D is obtained from sunlight and dietary sources. Traditionally it was thought that most people didn't require vitamin D from the diet provided there was enough exposure of the skin to the sun during the summer months. The World Health Organisation reports that 5 to 15 minutes of casual sun exposure of hands, face and arms (without sunscreen) two to three times a week during the summer months is sufficient to keep your vitamin D levels adequate. However this has not accounted for countries in high latitudes with lower UV exposure and low cloud cover, such as Ireland, where it is more difficult to measure how much is needed from sunlight for good health. The rising use of sunscreen (particularly on our pale, freckly skin) has also affected vitamin D levels. I think you see where I'm going, as we cannot rely on exposure to sunlight, it is very important to ensure that adequate vitamin D is obtained through diet to prevent any deficiencies and promote optimal health.

Dietary sources

Vitamin D is a fat soluble vitamin and it is found in some of our most commonly eaten foods like oily fish (including cod liver oil), meat (particularly liver), eggs and dairy products. It is also found in fortified foods such as low fat dairy products, breakfast cereals, and margarine/spreads. Including a variety of these in the diet will ensure adequate levels. (Advice on how to include these in the diet in a cost effective manner is covered in a previous blog post- Healthy eating on a budget). Moderate exercise (which we are all doing.......ahem!) also helps improve the body's use of vitamin D.

I hope this has helped shed some light on vitamin D- yes I did just say that!

Marie Hannon

Registered Dietitian