What it does: As a component of red blood cells, iron transports oxygen and carbon dioxide to and from cells. Also vital for energy production.

Deficiency Signs: Anaemia, e.g. pale skin, sore tongue, fatigue, listlessness, loss of appetite, nausea, sensitivity to cold.

Best food sources: Pumpkin seeds, parsley, almonds, prunes, cashew nuts, raisins, Brazil nuts, walnuts, dates, pork, cooked dried beans, sesame seeds, and pecan nuts.