Vitamin D3

pdf of a talk on D3 that I’m givng to the local U3A here:

D3 has lots of actions and is regarded by cell/molecular biologists as a hormone.
Hope its useful.
We can discuss it on here as I don’t use the blog interactively.


Excellent presentation.

You don’t have much to say about D3 and PD, which is fair enough given that your audience, U3A, is wider than just Parkinson’s. But, what is your view?

A paper by Willis et al. (2010) on the geographical epidemiology of PD, doesn’t give a clear message of an association between D3 and PD.

The maps, at county level, that they present show, to my eyes at least, a ridge of high prevalence, roughly south west to north east, from southern Texas to Maine. The D3 hypothesis would have expected a south (low) to north (high) gradient linked to decreasing amounts of sunlight.


Hi John,
Thank you. It was PD that made me aware of the huge importance of D3 in so many tissues.
Ther is along story of lower serum D3 in PD but its not an impressive difference, like your geographical insolation anlysis. Howerever there’s a lot more that can go wrong in D3 siganlling than serum level, lots of potential plausible reasons why PD may arise from errors in D3 signalling. Many oldies like me are D3-inadequate but only a few are PD.

Slide 11 and the reference cited are the link between D3 and PD. D3 combats Oxidative stress. Oxidative stress causing PD has a long history going back to the CA drug addicst (MPTP), and exposure to pesticdes such as rotenone. Berridge ( and others) are pointing the finger at the defences cells offer to oxidative stress. We may not need to have been poisoned if D3 levels are so low, or ineffective, in defending us against baseline oxidative stress. About 0.5% of oxygen in every breath ends up as reactive oxygen species, 24 /7. D3 provides very a large contribution to cells’ defences to those ROS.

D3 and other endogenous agents are the cornerstone of my experimental DIY ‘PD therapy’. I shall be describing them on my blog in the next few months, and will flag the posts here. As a cell biologist I approach it as I would a culture medium: what might my brain be lacking to help it combat ROS to function optimally. D3 is top of the list !

I find the vitamin D link confusing, for as I understand it, the majority of D comes direct through our sunlight. Therefore, indoor workers should have a lower build up than outdoor. I spent 20 working years in a Garden Centre, 90% outdoors, yet here I am with the same low vit D level.

In UK from Sept to March the sun is low in the sky and the UVB is absorbed by the atmosphere before it reaches our skin. So no D3 from sun in winter. D3 in the blood lasts about 13 days so blood D3 slowly drops through winter as the stores in our body fat run out.
In my own case I suspect I ran down to very low bloodD3 each winter and may have lost some Substatia nigra cells each winter, hence the PD now age 73.
The important thing is dosing with D3 now should offer the remaining cells protection.

Makes sense, and tyneside is in twighlight for 6 months