Micronutrient Deficiencies and Cardiovascular Disease: A Binational Analysis of NHANES and CHARLS

Micronutrient deficiencies are modifiable risk factors for cardiovascular disease (CVD), yet their relative importance and combined effects across populations require further characterization.We performed a binational analysis integrating cross-sectional data from the US National Health and Nutrition Examination Survey (NHANES, 2007-2018; n=3,848) and prospective data from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2018; n=11,391). Associations of specific micronutrient biomarkers (vitamin D, folate, vitamin B12, calcium, iron) and dietary patterns with CVD were assessed using multivariable-adjusted logistic regression, Cox proportional hazards models, and restricted cubic splines. A composite micronutrient deficiency score (MDS) evaluated cumulative risk.In NHANES, iron deficiency was independently associated with prevalent CVD after full adjustment (odds ratio [OR] 1.49, 95% confidence interval [CI]: 1.09-2.01), with a population prevalence of 23.4%. Although most prevalent (33.1%), vitamin D deficiency showed no independent association. Nonlinear analyses revealed a U-shaped relationship for iron (p-nonlinearity=0.003) and an inverse association for vitamin D (p-nonlinearity<0.001). A dose-response relationship was observed for cumulative deficiencies; participants with ≥2 deficiencies had 91% higher CVD odds (OR 1.91, 95% CI: 1.20-2.99). In CHARLS, frequent consumption of fruits/vegetables (adjusted hazard ratio [aHR] 0.81, 95% CI: 0.70-0.93), nuts (aHR 0.82, 0.71-0.95), and fish (aHR 0.85, 0.74-0.98) was associated with reduced incident CVD risk.Iron deficiency is an underrecognized independent risk factor for CVD, and multiple concurrent deficiencies synergistically increase risk. Plant-based dietary patterns are consistently protective. Findings advocate for iron status screening in cardiovascular risk assessment and emphasize holistic nutritional approaches.