Tuesday, 26 April 2011

Vitamin D

Back in February I had my regular blood test as usual. The lovely nurse, whom I usually see, told me that due to low light levels in Manchester, many people here often have vitamin D deficiency. I thought this was an interesting fact and strange I hadn't known about or heard about it before. Then, by sheer coincidence the results of my blood test revealed that I am indeed currently deficient in vitamin D. I thought this was an interesting fact and strange I hadn't known about or heard about it before. (Do I think my nurse is clairevoyant, lol,hell no!). I find this so hard to believe, now in April given the heatwave we are going through and the fact I have been out running in it everyday. I thought it would be nice to research and write a post on this vitamin just touching on its chemistry. I, myself, only knew what most people generally know I think, without looking anything up. That is, it is made in the skin when it is exposed to UV light. Deficiency among other things can produce brittle bones. Not good news for me since I recently ran the Brighton marathon. This is about as much as I knew about it anyway. It is a fat soluble vitamin, and in the skin, 7-dehydrocholesterol, a derivative of cholesterol is photolysed by UV light producing previtamin D3. The biologically active form being known as calcitrol. When synthesised in the kidney's it regulates among other things, the conc of calcium and phosphate in the bloodstream thus promoting the healthy mineralisation, growth and remodelling of bone. There are several types collectively, known as calciferol. I seem to be taking vitamin D3 or cholecalciferol. Chemically, the various forms of vitamin D are secosteroids i.e. steroids in which one of the bonds in the steriod rings is broken.The structural difference between vitamin D2 and vitamin D3 is in their side chains. The side chain of D2 contains a double bond between vitamin D2 and vitamin D3 is in their side. The side chain of D2 contains a double bond between carbons 22 and 23, a methyl group on carbon 24. It is a derivative of ergosterol, a membrane sterol and is produced by some organisms of phytoplankton, invertebrates and fungi in response to uv irradiation, D2 is not produced by land plants or vertebrates.
I found the following history interesting. The photosynthesis , of vitamin D evolved over 750 million years ago and played a critical role in the maintenance of a calcified skeleton in vertebrates as they left their calcium-rich ocean enviroment for land over 350 million years ago.

Vitamin D can only be synthesised via a photochemical process so early vertebrates that ventured onto land either had to go ingest foods that contained vitamin D because melanin in the skin hinders vitamin D synthesis.
One of the most important roles of vitamin D is to maintain skeletal calcium balance by promoting calcium absorption in the intestines, promoting bone resorption by increasing the osteoclast numbers, maintaining calcium and phosphate levels for bone formation, and allowing proper functioning of parathyroid hormone to maintain serum calcium levels. Historically, vitamin D3 was used to treat tb patients but has not been adequately investigated in controlled clinical trials.
Interestingly, vitamin D3 has also shown some anti-hiv -1 effects  in vitro , including the induction of  autophagy. In an epidemiological study of hiv positive women in tanzania, there appeared to be a correlation between reduced levels of vitamin D and speed of hiv disease progression. It is important to note that this still needs confirmation. To get deep into the chemistry, please look at this link


Monday, 25 April 2011

Marathon update

I know that this isn't the right blog for this lol but I feel its worth mentioning since I mentioned it in my previous post ;) 

Back home in Manchester now after my adventure in Brighton,and I did think of it as an adventure. Alot hillier than I expected but so much to do.Brighton Rocks!Gorgeous view of the sea and the pier from our hotel and I got to see a fair bit of the place on my run. Fantastic to meet Joe at last and her lovely other half and sweet daughter. We all spent a wonderful evening together. Thank you very much to Joe and Starfish for the most beautiful t-shirt ever I wore it with pride and it is rather salty now but I shall wash it gently and put it in my treasure trove. Well I did it, I completed a marathon and although it didn't go exactly according to plan I am very happy to have done this. I thoroughly enjoyed the run,the atmos was terrific as it always is at these events I was doing brilliantly, I was running well and was making good time for the first half, 13 miles. Then at mile 15 developed pain in the back of my left leg,this got progressively worse throughout both of my legs with the odd twinge of cramp. I knew what it was straight away, salt depletion and I knew I would be walking most of the rest of the way by mile 21 I couldn't run at all and my fingers had all swollen up so I went to the nearby paramedics who gave me a couple of salty drinks then I was on my way again,keeping my hands in the air as advised. I managed to run the last 50 metres over the finish line to lots of cheers. Got unexpectedly emotional because after all my training, efforts etc I had hoped to do this in 4.5 hours not the full 6.Britain has been in a heatwave this past week and I just cannot run in the sun, just as I struggle to swim in warm water.All has to be cool-ish for me. However I did it and got my medal damn it! There were some poor souls worse off than me. My fingers were normal size again by 8.30 ish after a meal. Thanks to our lovely hotel staff for putting on an early breakfast for us. Thanks to Joe and her family for coming along to meet and support me. I hope your journey home was fine and didn't take too long. Thank you to everyone who has sponsored and supported me, it really does mean alot to me and does make a difference. At mile 16 a lady with a tannoy stopped me and gave a shout out for Starfish So thats phase 1 complete, now for the more important phase 2,collecting  sponsorship. So now I'm at the recovery and rebuilding of the body stage. Lots of rest, fluids and sleep.
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I am grateful for any feedback and comments. Thanks for reading and don't be a stranger xxx