Frank's Comments:
We have been hammering on the need to maintain high blood levels of Vitamin D3 for quite some time now. I put many articles on this site detailing the profound impact vitamin D3 has on immune function and incidence of the three big killers of the aging population.
Now here comes a meta-analysis of a large collection of studies around the world, all pointing at drastic reductions in death rates due to these killers when blood levels of 25-hydroxyvitamin D are in the higher range. These studies suggest that the OPTIMAL value of vitamin D that you’re looking for is 45-52 ng/ml (115-128 nmol/l).
You can find out what your levels are by asking your doctor for a blood test called a 25(OH)D, also called 25-hydroxyvitamin D. Your best source of vitamin D3 (the only form you should be taking in a supplement or food additive) is Cod Liver Oil. There is virtually no chance of vitamin D toxicity from taking 1-2 tablespoons of cod liver oil per day for the average person. More likely is that vitamin A toxicity will occur first, and you would need about 20 times that dose daily to reach chronic toxicity levels. You can ask your doctors, but the odds are good that they won't have a clue as to the risk, and will err on the safe (their opinion) side by telling you not to supplement. Don't buy it - research it yourself! Read the recent research and protect your health with proper exposure to sunlight and good old cod liver oil.
Background: Ecological and observational studies suggest that low vitamin D status could be associated with higher mortality from life- threatening conditions including cancer, cardiovascular disease, and diabetes mellitus that account for 60% to 70% of total mortality in high-income countries. We examined the risk of dying from any cause in subjects who participated in randomized trials testing the impact of vitamin D supplementation (ergocalciferol [vitamin D2] or cholecalciferol [vitamin D3]) on any health condition.
Methods: The literature up to November 2006 was searched without language restriction using the following databases: PubMed, ISI Web of Science (Science Citation Index Expanded), EMBASE, and the Cochrane Library.
Results: We identified 18 independent randomized controlled trials, including 57 311 participants. A total of 4777 deaths from any cause occurred during a trial size–adjusted mean of 5.7 years. Daily doses of vitamin D supplements varied from 300 to 2000 IU. The trial size– adjusted mean daily vitamin D dose was 528 IU. In 9 trials, there was a 1.4- to 5.2-fold difference in serum 25-hydroxyvitamin D between the intervention and control groups. The summary relative risk for mortality from any cause was 0.93 (95% confidence interval, 0.87- 0.99). There was neither indication for heterogeneity nor indication for publication biases. The summary relative risk did not change according to the addition of calcium supplements in the intervention.
Conclusions: Intake of ordinary doses of vitamin D supplements seems to be associated with decreases in total mortality rates. The relationship between baseline vitamin D status, dose of vitamin D supplements, and total mortality rates remains to be investigated. Population-based, placebo-controlled randomized trials with total mortality as the main end point should be organized for confirming these findings.
Author Affiliations: International Agency for Research on Cancer, Lyon, France (Dr Autier); and the European Institute of Oncology, Milano, Italy (Dr Gandini).
