I like to call potassium the “hidden bone guardian,” as the role it plays along with sodium in maintaining critical fluid balance is widely known, but potassium’s service to bone health is less well appreciated. This guardianship role relates mainly to the ability of certain alkalinizing potassium compounds to neutralize the bone-depleting acids that are produced during everyday normal metabolic processes. In maintaining the acid–alkaline balance in our bodies, potassium prevents too much calcium from being excreted in the urine.

Diets low in potassium increase net urinary calcium loss, whereas diets high in potassium reduce it. In fact, dietary potassium can offset the excretion of absorbed calcium to such an extent that eating one medium baked potato or one large banana can conserve about 60 mg of calcium! Supplemental potassium in the form of potassium salts such as potassium bicarbonate and potassium citrate can also help decrease urinary loss of calcium.

The transition in our diet in recent generations to one that is lower in fruits, vegetables, and legumes has resulted in significantly decreased potassium intake. Yet we know that higher potassium intake, particularly in the form of fruits and vegetables, is directly associated with overall higher bone mineral density and less bone loss — all the more motivation for us to renew our “5–10-a-day” pledge!

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