Boron supplementation may reduce the excretion of calcium. Aluminium containing antacids can inhibit calcium absorption. Excessive calcium can interfere with the absorption of copper, iron, magnesium, manganese and zinc. Calcium helps in the absorption of vitamin B12. Calcium and magnesium and calcium and potassium are related in that high levels of one can produce low levels of the other.
Excessive potassium can lower calcium levels.
Calcium and phosphorus work together to form healthy bones and teeth. If your phosphorus intake is too high your body excretes the extra and calcium along with it. Large quantities of sucrose can enhance calcium excretion. Vitamins A and C enhance the transport of calcium through cell membranes. Vitamin B6 may enhance calcium function.