Calcium is the most abundant mineral in the body, with “more than 99% of it residing in your bones and teeth,” says the Cleveland Clinic. The rest helps muscles, nerves, and the heart function. Since the body cannot produce calcium, it must come from food or supplements. But some foods actually reduce calcium and weaken bones.

Soda
Colas contain phosphoric acid, which “can block calcium absorption and cause your body to lose calcium from bone tissue.” Added sugar worsens inflammation, raising fracture risk.

Salt and Caffeine
Too much sodium makes the body excrete calcium through urine, while excess caffeine also drains calcium. “Having 1–2 cups of coffee daily is considered safe,” but more can weaken bones.

Alcohol
Heavy drinking lowers vitamin D and slows bone-building cells. More than one drink a day for women, or two for men, increases osteoporosis risk.

Red Meat and Certain Vegetables
Processed meats high in phosphorus and vegetables like spinach or rhubarb (rich in oxalates) interfere with calcium absorption. Experts suggest moderation and balancing with calcium-friendly foods like kale, broccoli, and lean proteins.