Iron

Restores hemoglobin in deficient individuals; reduces fatigue and improves exercise capacity.

Common side effects: constipation, nausea, dark stools. Iron overdose is a leading cause of fatal poisoning in young children — keep out of reach.

Ferrous sulfate, fumarate, and bisglycinate are common forms. Vietnam runs maternal-child supplementation programs because iron-deficiency anemia remains prevalent, particularly in pregnancy.