Some medical texts have said that overdose of vitamin D can cause vascular and even metastatic calcification, because high vitamin D levels raise calcium levels Apparently this only applies to synthetic vitamin D and not to that obtained by sun exposure. I live in the UK and have for 8 years or so been supplementing with 5000 to 6000IUs of vitamin D3 per day during Winter. My MS symptoms (except bladder) are much reduced, but now I am worried that although a cornerstone of the OMS regimen, high levels of vitamin D may not be good for me in other ways. Does anyone know anything about this?
My understanding is this:
The OMS protocol advises keeping our Vit D levels at around 150nmol/L to 200nmol/L (UK measurements). Problems with calcification arise when levels hit around 400nmol/L.
So although we are taking more than the recommended dose by most GPs standards, we are unlikely to damage our health.
The thing to look at is the level of Vit D in your blood, rather than how much you are taking. I take much more than you - 10,000iu per day - and my level is around 200nmol/L. Our bodies don't 'build up' the level, which is why people often have to take a megadose to get their levels up initially.
I hope this gives you some reassurance.