18–27 mg elemental iron daily, taken on an empty stomach with vitamin C (e.g., orange juice) for optimal absorption. If stomach upset occurs, take with a light meal, though absorption will be slightly reduced.

15–30 mg daily with food to minimise nausea. Do not exceed 40 mg/day without medical supervision, as chronic high-dose zinc can cause copper deficiency and worsen hair loss.

2500–5000 mcg daily with a meal. Take consistently for at least 3–6 months to assess benefit.

500–1000 mcg daily in the morning with food. Methylcobalamin is the active form and is better absorbed than cyanocobalamin. If you take metformin or PPIs, consider a sublingual tablet or spray for better absorption.