A recent trial showed that low blood levels of of Vitamin D levels were associated with an increased risk of subsequent mortality among African Americans and non-African Americans.
To date, there are no published data from controlled trials designed specifically to assess the effect of vitamin D supplementation on total mortality. Autier and Gandini conducted meta-analysis of 18 trials involving frail, elderly individuals of European descent taking ordinary doses of vitamin D supplements often with the addition of calcium and they reported a significant 7% reduction in total mortality risk among vitamin D supplement users with a mean daily dose of 528 IU and a mean follow-up time of 5.7 years.
In this Trial, the Authors observed a significant trend of increasing risk of all-cause mortality with decreasing levels of serum 25(OH)D (Vitamin D).
Those with the lowest levels of Vit D had an 80% increased mortality risk compared with those with the highest levels. The results were same even in patients with heart attacks, bypass surgery, diabetes and high blood pressure. It was found that normal Vitamin D levels in the blood reduced mortality in each of the groups. The trial advises individuals to maintain their Vit D levels in the normal range.
I would suggest to get a Vitamin D level done and see if its low. Vitamin D supplement can be then taken to increase these levels to normal range.
In the hospital where I work, 80% of the hospital employees were found to have low Vitamin D levels. The main reasons for this is inadequate exposure to sunlight and indoor working!
So it would be advisable to increase your exposure to the sun or take Vit D supplements if the are blood levels are low!