Scientists know that vitamin D deficiency is unhealthy. However, a study suggests that too much vitamin D isn’t healthy either. The research is based upon blood samples from 247,574 people.[1] Vitamin D is important in helping calcium get to our bones, and so reducing the risk from falls as well as the chance of broken hips. Studies suggest that vitamin D is also beneficial in preventing depression, cardiac disease and some kinds of cancers.
The outcomes from research also support the benefits of vitamin D with regards to mortality risk. However, the study results also reveal higher mortality in those with too much vitamin D in their blood. The researchers found higher mortality in individuals with a low level of vitamin D in their blood, but to their surprise, they also found it in those with a high level of vitamin D in their blood. A graph can be drawn showing that it could be harmful with too little as well as too much vitamin D.
Mortality is 2.31 times greater when the blood has under10 nmol of vitamin D for each litre of serum, and mortality is 1.42 times greater when the blood contains over 140 nmol of vitamin D for each litre of serum. Both of these values are in comparison to 50 nmol of vitamin D per liter of serum, the value where the lowest mortality rate was observed.
The data material was collected from a wide range of ages. Those who participated had approached their own medical practitioners for a number of reasons and had had vitamin D levels measured in that context.
The scientists emphasize that while they don’t know the reason for the higher mortality, they believe that the study results could be used to question the wisdom of those who maintain that you can’t ever get too much vitamin D.
Although the research can indicate an association between a high level of vitamin D and mortality, the higher risk cannot be explained.
