Rather than a single miracle vitamin, adults aged 70 and older typically benefit most from targeted micronutrients that address age-related absorption declines, including vitamin B12 (to support neurological function and red blood cells), vitamin D and calcium (to preserve bone mineral density and prevent fractures), and vitamin C or D for immune resilience. Consulting a primary care physician for routine blood panels helps identify exact personal deficiencies rather than relying on unguided high-dose supplementation.