Can we excess on Vitamin D?
Excessive Vitamin D is linked to cardiovascular disease
One cannot deny the findings in this research (1), published in February, that excessive blood serum levels of vitamin D are as linked to cardiovascular disease as are levels that are too low.
However we need to ask ourselves: what the likelihood, in the UK, of being vitamin D deficient versus having an excess? In the UK we only get sufficient sunlight to synthesis vitamin D between April and September. I’ve written about our need for Vitamin D before, and although we do need to be wary[more] of having too much it is far easier in this country to not get enough. Our children spend much longer inside than ever before causing rickets to re-emerge from our Victorian past and when they do go out they’re slathered in factor 50 from head to toe. Even as adults our bodies rarely see sunlight during the working week.
Yes, we need to be weary regarding supplements and overdosing on single nutrients. We need to be educated so that any supplements are: effective, suitable for our needs; not contraindicated for medication (DrugNutrientInteractions); and are the correct type and in the correct formulation. It would be marvellous to get sufficient vitamin D from food but that’s not straightforward and there are only so many sardines one can face. In order to reach the upper limits cited in the study we would need to take at least 100ug of vitamin D for 2-5 months (2). Most multi-vitamins will have vitamin D at levels of 10ug and even individual supplements are generally at 25ug.
We also need to be aware of our magnesium levels as vitamin D absorption and metabolisation is dependent on this, if your vitamin D levels remain stubbornly low, this may be the reason. In addition Vitamin D interacts with the other fat-soluble vitamins A and K2, with vitamin A having a protective effect against excessive levels of Vitamin D. The study above didn’t say whether the Danes who had high serum levels of Vitamin D were supplementing, if they were, whether they were supplementing in isolation or taking the more metabolically active form of Vitamin D3 (cholecalciferol) rather than D2.
As ever supplementation is never clear cut, an excess of anything is always going to run risks. However that is not to say that some individuals would not still benefit from an additional intake of certain nutrients. Sometimes supplementation is the most straightforward way of achieving this.
If you feel that you need further advice on Vitamin D supplementation for any member of your family that is housebound or covers up regularly contact firstname.lastname@example.org
By Saffron Rogerson
18 March 2015