The Sunshine Vitamin
Vitamin D is good for bone strength and may also help fight off Covid-19 infection, writes Ian Madigan
Vitamin D is often called the ‘sunshine vitamin’ and the sobriquet is apt, because the best way to source it naturally is through a little sunbathing. When sunlight falls on your skin, the body uses the UV radiation to create vitamin D from cholesterol. The next best sources of the vitamin are oily fish such as salmon or mackerel, and to a lesser extent eggs and beef, but you’d need to consume large amounts of these foods to better sunshine or a vitamin D supplement.
People require vitamin D primarily to absorb calcium, the mineral that strengthens your bones. It is also used by the body to aid cell growth, keep your immune system ticking over and regulate blood pressure. Vitamin D deficiency comes with serious consequences, including weak and brittle bones (osteoporosis), and a higher risk of developing certain cancers, diabetes and depression.
Scientists in Trinity College Dublin recently stated that vitamin D helps the body to fight the Covid-19 infection. In fact, so strong was the evidence linking vitamin D deficiency and increased Covid-19 mortality, that the TCD academics urged the government to recommend vitamin D supplements to the Irish population during the Covid-19 pandemic. Professor Rose Anne Kenny, who was involved in the meta-analysis research, said that it didn’t matter if the study caused a rush for vitamin D supplements. “This is no time to hang around,” she reportedly added.
Relying on sunlight for your vitamin D won’t be enough in the autumn and winter months, so taking a supplement is the best solution. The body can store vitamin D for between 30 and 60 days, so make the most of the autumn sunshine. However, don’t overdo the sunbathing. The Irish Cancer Society — following World Health Organisation advice — recommends five to 15 minutes of casual sun exposure to hands, face and arms, two to three times a week, to keep your body topped up with vitamin D. That guidance is applicable for sunshine between late March and early September.
The risks of developing skin cancer from too much sunbathing are high for the Irish population – skin cancer is the most common form of cancer in Ireland. David Leffell, a dermatologist with the Yale School of Medicine, argues that the risks might outweigh the gains with sunbathing for vitamin D.
“There are claims that one needs to get a certain amount of sun exposure every day in order to produce enough vitamin D to be healthy. It’s just not true. The majority of people can source their vitamin D from nutritional supplements and from vitamin D-fortified foods.”
Nevertheless, it’s estimated that vitamin D deficiency affects almost half of the worldwide population. More recent research from University College Cork suggests that one in eight people in Ireland has insufficient vitamin D levels.
The HSE recommends that all babies aged 12 months or younger should be given vitamin D supplements, while in the UK the NHS recommends that people consume 10 micrograms of vitamin D a day.
In Ireland, use of vitamin D supplements is very low. The Irish Longitudinal Study on Ageing, published by TCD in April 2020, notes that only one in ten people aged 55 and over take a vitamin D supplement during winter. More generally, just 4% of men and 15% of women in Ireland take vitamin D supplements.
The best advice regarding vitamin D is to source some of it from a healthy diet and a little more from sensible sunbathing. Also, take vitamin D supplements in winter.
‘One in eight people in Ireland has insufficient vitamin D levels’