Generally, taking a standard daily multivitamin that does not exceed 100% of the Recommended Daily Allowance (RDA) is safe to take long-term. However, if you eat a balanced diet, they are often unnecessary. The main risk comes from high-dose supplements, particularly fat-soluble vitamins (A, D, E, and K) and minerals like iron, which can accumulate in the body and cause toxicity over time. I recommend having your healthcare provider review your supplement routine annually to ensure you still need them and are taking a safe, appropriate dosage for your specific health needs.