Lack of vitamin D in Donegal

Sir, – Based on his research, Dr Martin Coyne concludes that in Donegal, even if you lie out naked in the sun on a cloudless winter day, you still won’t get enough vitamin D (“Vitamin D levels in Donegal far worse than national average,” Home News, August 14th).

If you lie out naked round here, vitamin deficiency will be the least of your problems. – Yours, etc,

Dr JOHN DOHERTY