4. Discussion
micronutrient deficiencies, insufficiencies, mineral deficiencies, chronic disease
DISEASE, CHRONIC DISEASE
Older adults often take over-the-counter supplements to improve their health. However, previous studies on multivitamins show that they fall short of reducing chronic disease risk [These results appear to challenge the general perception of nutrition status in older adults. Older adults were selected for this trial because advanced age is generally considered to be a prescription for multiple vitamin and mineral deficiencies and would present an ideal cohort for an MV/MM intervention. This idea has been supported by previous reports on nutritional biomarkers, showing that overt micronutrient deficiencies are somewhat commonplace in adults over the age of 50 who do not regularly consume dietary supplements [Although deficiencies and insufficiencies were not common, suboptimal vitamin status, which is presently defined as having blood vitamin concentrations below optimum, was present in a significant number of healthy older adults. However, “optimal” status is a much more nuanced concept than deficiency since the health benefits of optimal versus suboptimal status are subtle and less precisely defined. There are some generally agreed-upon ideal blood concentrations for certain micronutrient biomarkers (such as vitamin C and vitamin D), but optimum blood concentrations for many vitamins are based on very limited scientific evidence. With these caveats in mind, 33 of 35 participants in this study were suboptimal in at least one of eight vitamins at baseline, despite consuming what appeared to be a rounded diet. Most common were shortfalls in three to five of eight vitamins (26 of 35 participants), with four having one suboptimal vitamin concentration and three having five suboptimal vitamin concentrations. This is where the impact of MV/MM supplementation is clear: those in the MV/MM group improved their vitamin status by the end of the study, whereas those in the placebo group either saw no change or had their vitamin status decline over time.This study provides additional considerations for those designing MV/MM studies in the future. Unlike previous reports that focused on disease risk, this study did not examine disease-related outcomes. Instead, a focus was placed on a more fundamental question that relates MV/MM supplement use to improvement in micronutrient status. It is our position that this detailed approach is missing from many large MV/MM supplement trials. The results above show that the need for micronutrient supplementation varies by individual, and the response to the MV/MM intervention is equally variable. While some individuals in the MV/MM group improved their plasma vitamin concentrations dramatically upon supplementation, others only experienced marginal changes—thus, improvements to overall vitamin status were present but not universal. If consuming an MV/MM supplement does not guarantee changes in micronutrient status, how can one expect to observe changes in health outcomes? Based on these results, the recommendation would be to include micronutrient biomarkers as fundamental benchmarks in any clinical study on MV/MM supplements and to only look for changes in disease risk in those who showed improved micronutrient status.Furthermore, instead of continuing with large and involved clinical trials that focus on MV/MM use and the reduction of chronic disease risk, it may be more prudent to focus on the ways MV/MM supplements influence markers of health status. Existing studies where relatively healthy older adults were the focus, such as the current study, have already provided evidence that daily MV/MM supplementation may improve indices of metabolism which potentially lowers the risk for pathophysiologies of aging. For example, a daily MV/MM supplement given to older adults limited plasma homocysteine levels, potentially through maintenance of the 1-carbon methyl cycle [Finally, this study had several strengths and weaknesses. This study was limited to participants within driving distance of the Oregon State University campus in Corvallis, Oregon. Thus, the study population was predominantly Caucasian (94%), all with post-high school education, and most (94%) with college degrees. They were also rigorously screened to exclude significant co-morbidities. Despite this, the dietary micronutrient intake and the prevalence of supplement use in these participants was similar to much larger trials with more diverse populations, as reported in NHANES data [