Are health supplements helpful or overhyped?A review of 19 meta-analyses shows mixed results on the effects of multivitamin and mineral (MVM) supplementation on health outcomes.
The meta-analyses comprised data from approximately 5.5 million individuals, including 333,943 women during pregnancy and 904,947 children born to mothers who took MVM supplements during pregnancy. [Ageing Res Rev 2026;114:102965]
A meta-analysis of randomized controlled trials (RCTs) showed that MVM use reduced stress (standardized mean difference [SMD], 0.35), anxiety (SMD, 0.32), mild psychiatric symptoms (SMD, 0.30), fatigue (SMD, 0.27), and confusion (SMD, 0.23) in healthy adults. “Further analysis indicated that supplements containing high doses of B vitamins were more effective in improving mood states compared with those with a broader range of micronutrients at lower doses,” the investigators said.
RCT evidence showed that MVM use improves immediate free recall (SMD, 0.32) in cognitively intact adults, and global cognition (MD, 0.07) and episodic memory (MD, 0.06) in older adults without dementia.
MVM use reduced the incidence of fragility hip fracture in another meta-analysis (odds ratio [OR], 0.49).
MVM use also appeared protective against colorectal cancer (relative risk [RR], 0.92) and certain paediatric cancers (brain tumours: OR, 0.73, leukaemia: OR, 0.64, and neuroblastoma: OR, 0.53).
MVM use did not affect COVID-19 outcomes, including intensive care unit admission rates (RR, 0.94), length of hospital stay (WMD, –0.20 days), O2 saturation improvement (WMD, 0.04), and mortality (RR, 0.96) among hospitalized patients.
Other meta-analyses showed no association between MVM use and all-cause mortality (RR, 0.98), mortality due to vascular causes (RR, 1.01) or cancer (RR, 0.96), breast cancer risk (cohort: RR, 0.99 and case-control: OR, 1.00), prostate cancer incidence (OR, 1.11), and prostate cancer progression and mortality (OR, 1.10).
MVM use did not affect visual acuity (weighted MD [WMD], 0.02), but it did increase the risk of macular degeneration progression (RR, 2.08).
In a meta-analysis of studies evaluating individuals without pre-existing cardiovascular disease (CVD), MVM use was associated with a lower risk of coronary heart disease (CHD; RR, 0.88), but not stroke (RR, 0.98) or mortality (CHD: RR, 1.02, CVD: RR, 1.00, and stroke: RR, 0.95).
Another pooled analysis showed that MVM use led to a small but substantial reduction in systolic blood pressure (SBP; WMD, –1.31 mm Hg) but not diastolic BP (DBP; WMD, –0.71 mm Hg). Subgroup analyses found greater BP reductions in individuals with hypertension (HTN; SBP: –7.98 mm Hg) and chronic diseases (SBP: –6.29 mm Hg and DBP: –2.32 mm Hg) but not in normotensive individuals (OR, 0.92).
Results from another meta-analysis indicated that MVM use reduced the number of infection episodes in younger adults (<65 years; WMD, –1.20) but not in healthy older adults (≥65 years; WMD, 0.06). In a subgroup analysis of undernourished older adults, MVM use for at least 6 months was associated with fewer infection episodes (WMD, –0.67).
Another pooled analysis showed that MVM use was associated with a lower risk of cataracts (cortical: RR, 0.81, nuclear: RR, 0.73, and overall: RR, 0.66), but not of posterior subcapsular cataracts (RR, 0.96) or cataract surgery (RR, 1.00). RCTs provide evidence supporting a protective effect against nuclear cataracts (RR, 0.66), particularly in older adults (65–74 years; RR, 0.57).
MVM use appeared protective against gestational HTN in one RCT (RR, 0.62), but observational results suggest otherwise (OR, 0.91; gestational HTN or preeclampsia).
Another meta-analysis found no association between MVM use and preeclampsia risk (RR, 0.85), but one RCT reported a protective effect (OR, 0.18).
Observational studies suggested a protective effect of MVM use on small-for-gestational-age births (RR, 0.77) and congenital anomalies, such as congenital CV (RR, 0.83), limb (RR, 0.68), neural tube (RR, 0.67), and urinary tract defects (RR, 0.60), but pooled results and RCT evidence did not show an effect on preterm birth (RR, 0.84), low birth weight (RR, 0.79), or stillbirth (RR, 0.78).
“The evidence for MVM use to promote healthy longevity remains limited and inconclusive,” the researchers noted. “As the conversation around healthspan continues to evolve, recommendations for supplement use must be grounded in solid scientific evidence rather than driven by consumer perception or commercial messaging.”
The results underscore the importance of shifting from generalized approaches to more targeted, personalized supplementation strategies to support healthspan and longevity, they added.