What it does: Enables nutrients to move in and waste products to move out of cells, promotes healthy nerves and muscles, maintains fluid balance in the body, relaxes muscles, helps secretion of insulin for blood sugar control to produce constant energy, involved in metabolism, maintains heart functioning, stimulates gut movements to encourage proper elimination.

Deficiency Signs: Rapid irregular heartbeat, muscle weakness, pins and needles, irritability, nausea, vomiting, diarrhoea, swollen abdomen, cellulite, low blood pressure resulting from an imbalance of potassium: sodium ratio, confusion, mental apathy.

Best food sources: Watercress, endive, cabbage, celery, parsley, courgettes, radishes, cauliflower, mushrooms, pumpkin, molasses.