Micronutrients are vitamins and minerals needed in small amounts for normal body functions. Deficiencies can affect health and development; iron, vitamin A and iodine are examples. Iron deficiency can cause anaemia, but anaemia also has other causes. Tiredness alone cannot identify a deficiency. Varied foods and appropriately fortified foods can help meet nutritional needs. Beans, vegetables and suitable animal-source foods can contribute within a balanced diet, but no single food guarantees adequate nutrition. Persistent fatigue, poor growth or other concerns needs professional assessment. Do not diagnose a deficiency from symptoms or start high-dose supplements from chat advice. Pregnancy, childhood and existing medical conditions require individual guidance about testing, diet and supplements.