In my last post I said the jury was out on whether or not the slight increase in my vitamin D level could be attributed to my recent sun exposure. To recap, in my first two blood tests my vitamin d level went from 30 nmol/l to 37 nmol/l after 175 minutes of sun exposure, albeit mostly in Scotland where during late March and early April one would not expect much UBV light, the ultraviolet responsible for producing vitamin D.
To be honest I was a little disappointed it hadn’t gone up by much, but at the same time not very surprised for the aforementioned reason. It had been a struggle to get any time in the sun at all, not least because there wasn’t very much of it about! However, I have persevered and although in my last post I said I would test again in two weeks, I managed so little sun that I thought I might as well give it a four-week gap. And of course, towards the end of April and early May the sun is getting stronger so hopefully the results would be more encouraging.
In total I managed about 6.5 hours of sun in four weeks. It was relatively evenly spaced across the four weeks, but not days, so although my daily average was about 15 minutes, I achieved this in periods of as little as 10 minutes and as much as one hour. In general I tried to make sure it was around 11am - 12 pm when the sun is strong, but perhaps not too strong. I should point out that I have not got even remotely sun burned, or tanned, though perhaps I’m a little less anemic looking than when I started!
But what you want to know of course is has it worked? My latest blood test result is a great improvement at 54 nmol/l, which lifts me out of the insufficient (25-49 nmol/l) and into the normal range of 50 – 200 nmol/l. Admittedly only just into the normal range and I haven’t built up any reserve yet to take me through next winter (is that possible?). Still, given that I have not been taking vitamin D supplements, nor altering my diet, my little experiment proves that one can raise vitamin D levels through sunshine alone.
I intend to continue with my sunshine exposure, but now the sun is getting much stronger, I think I will be limiting myself to 20 to 30 minutes at a time, perhaps longer if it is earlier or later in the day (I think common sense should prevail), which I think will be more than sufficient to continue building up some reserve. I will re-test sometime in the autumn and as always, let you know how I get on!