The most valuable ingredient of lemon, next to vitamin C, is citric acid, of which it contains 7.2 per cent. Lemon contains more potassium than apple or grapes, which is beneficial to the heart. Lemon is very much useful in maintaining the health of the teeth and the bones. The vitamin C content of lemon helps considerably in calcium metabolism. Tonsillitis is one condition that causes a lot of pain and distress indeed, however there is this one natural treatment for tonsillitis.