The one problem that my initial blood tests showed was a minor Vitamin D deficiency. So my GP prescribed vitamin D, which I found ironic as someone who has always believed in the merits of a balanced diet over supplements.
Coincidentally, I had just received some free multivitamins and my GP correctly warned me not to take them until after I had finished the prescribed course. This is because too much vitamin D can cause problems, including the removal of calcium from bones. This is strange, as one of the main problems caused by a deficiency is failure to absorb enough calcium. So vitamin D is subject to the Goldilocks theory and too much or too little are both bad. Of course, what is “just right” is subject to debate.
At the time, I put down my vitamin D deficiency to my brown skin and didn’t think much more about it. I then learnt about new draft scientific advice to the UK Government to the effect that many more people in the UK probably need vitamin D supplementation than was previously thought. This is still draft advice and therefore not yet reflected in the official advice. The official
One of the main sources of Vitamin D is that it is made in the body under exposure to summer sunlight. Another application of Goldilocks, in that you need enough sun to make enough vitamin D but not so much that you burn. I did wonder if my deficiency might be caused by not cycling since my accident, and therefore reduced time in the sun. However, vitamin D is stored in the body for months, so this probably is not the cause, though it might have reduced slightly.
I look forward to the final scientific advice, as the whole area of vitamin D seems quite poorly understood. Beyond regulating Calcium, there seem to be a range of possible problems from having too little. These include, from the articles mentioned above:
- musculoskeletal health, including rickets in children, and osteomalacia in adults which can cause the person’s bones to become weak and painful, and hamper mobility
- heart disease,
- type 1 diabetes,
- multiple sclerosis.
On the other hand, too much can result in:
- excess calcium which can be deposited in and damage the kidneys.
- calcium being removed from bones, which can soften and weaken them.
- weight loss,
- poor appetite.
- anomalies in heart rhythms and mental confusion
The NHS recommends the following supplementation – 10 micrograms per day for adults falling into the groups where they do recommend it. They also set the upper limit at 25mg. On the other hand, the livestrong article I referenced sets the upper limit at 100mg, citing the University of Rochester Medical Center. So, what is too much is open to debate. My prescription is for 500mg per week (i.e. about 70mg per day) and this is a deliberately high dose to top up my level for 12 weeks.
The other important number is the level that is actually measured and which resulted in my diagnosis. The Guardian ran an earlier article on what this should be and it seems to say that below 30nmol/litre is bad, 50nmol/litre is probably about right but some think it should go up to 100nmol/litre. So I had to ask what my level was and it was actually measured at 39nmol/litre so it doesn’t seem that bad. However, given all the uncertainties, I am left wondering whether there might be some link to my accident. I will certainly keep on eating oily fish, though I will have to eat more to increase my levels.