#400 Vitamin D and Mortality-Don’t bet your life on it!
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Vitamin D supplementation does not reduce all-cause mortality, cardiovascular events, or cancer incidence. Effects on cancer mortality are inconsistent with most systematic reviews and the largest randomized controlled trials (RCTs) showing no effect.
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- 11 systematic reviews1-11 from the last 3 years, 12-80 RCTs, 70,278-182,804 patients. Adults (most RCTs average age >50, some “healthy” populations, some including chronic diseases), vitamin D (varying doses, example 400 international units (IU) daily to 100,000 IU monthly) compared to placebo/no treatment. Follow-up ~5 years (range 7 months-12 years).
- All-cause mortality :1-5
- Four systematic reviews:1-4 no difference from placebo. One other5 had an Odds Ratio 0.95 (95%CI 0.93-0.99) (event rates not reported). Insufficient details provided to evaluate why results differ.
- Cardiovascular disease (RCTs included patients with/without cardiovascular disease):
- Cardiovascular events:1-3,9-11 No difference.
- Cardiovascular mortality:3,5,9-11 No difference.
- Cancer (RCTs included patients with/without cancer):
- Cancer Incidence:1,2,4,9,10 No difference.
- Cancer mortality:1,4,9-11 Inconsistent results:
- Four systematic reviews:1,4,9,11 No difference. One systematic review10 not including largest RCT of bolus-dosing found difference, but event rates not provided, and largest RCTs showed no effect.
- Subgroup analysis of daily versus bolus-dosing:4,9,10 No difference.
- Four systematic reviews:1,4,9,11 No difference. One systematic review10 not including largest RCT of bolus-dosing found difference, but event rates not provided, and largest RCTs showed no effect.
- Adverse events: No difference.
- Limitations: Some systematic reviews missing metagraphs, heterogeneous populations, different dosages (daily versus boluses; various doses).
- Guideline12 suggests supplementation in those >75 years old based on a non-statistically different sub-group analysis.2
- In the general population and in those with low vitamin D levels, vitamin D does not prevent fractures13 or respiratory infections.14 High-dose bolus vitamin D may increase fracture risk.15
- Other interventions may have a larger impact on cancer mortality. Exercise interventions of 2-32 weeks with observational follow-up of 1-96 months reduce cancer mortality from 22% to 14% and cancer recurrence from 14% to 7%.16








Maybe the authors should consider if it’s the source vitamin D that matter, ie. sunshine