Nutr Rev. 2014 Jan;72(1):48-54. doi: 10.1111/nure.12090. Epub 2013 Dec 13.
Heaney RP, Creighton University, Omaha, Nebraska, USA.
Presented here is a system to standardize clinical studies of nutrient effects, using nutrient-specific physiological criteria. These guidelines are based mainly on analysis of the typical sigmoid curve of biological response to nutrients and are intended for design, interpretation, and pooling of studies of nutrient effects. Five rules have been articulated for individual studies of nutrients, and six for systematic reviews and/or meta-analyses.
Rules for individual clinical studies of nutrient effects.
- 1. Basal nutrient status must be measured, used as an inclusion criterion for entry into study, and recorded in the report of the trial.
- 2. The intervention (i.e., change in nutrient exposure or intake) must be large enough to change nutrient status and must be quantified by suitable analyses.
- 3. The change in nutrient status produced in those enrolled in the trials must be measured and recorded in the report of the trial.
- 4. The hypothesis to be tested must be that a change in nutrient status (not just a change in diet) produces the sought-for effect.
- 5. Conutrient status must be optimized in order to ensure that the test nutrient is the only nutrition-related, limiting factor in the response.
Henry Lahore, the founder of VitaminDWiki, believes that #5 is impossible.
- Many people are deficient in many conutrients/co-factors
- which includes Magnesium, Omega-3, Vitamin K2, Vitamin B12, etc
- There is no consensus of the levels needed to optimize any of those nutrients
- This lack of consensus is similar to the lack of consensus on optimal Vitamin D level: 20 ng, 30 ng, 40 ng, 50 ng, . . .
- Vitamin D clinical trials should be based on Vitamin D tests – Aug 2017 co-authored by Henry Lahore