What Foods Should Not Be Consumed While Taking Calcium Supplements?

If calcium supplementation is not done correctly, it can easily affect the absorption of calcium. When taking calcium tablets, foods containing oxalic acid, phytic acid, and excessive salt should be avoided.

Oxalic acid is a substance commonly found in vegetables. If foods high in oxalic acid are frequently consumed together with calcium-rich foods such as tofu, dried tofu, and milk, insoluble calcium oxalate will be formed, which can lead to the formation of urinary stones. Research has shown that boiling vegetables such as spinach and amaranth can remove 40% to 70% of the oxalic acid content.

Phytic acid is found in rice and white flour. When phytic acid combines with calcium in the digestive tract, it forms phytate calcium magnesium salt, which cannot be absorbed by the body, greatly reducing the absorption of calcium. Therefore, soaking rice in warm water for a while can help decompose most of the phytic acid in the rice. Fermented flour products also secrete phytase, which can hydrolyze the phytic acid in the flour and avoid affecting the absorption of calcium.

Additionally, calcium supplements should not be consumed with fatty foods, as the fatty acids produced after lipid digestion bind with calcium and are difficult to absorb. Eating excessive amounts of meat and eggs per meal should also be avoided as they contain high levels of phosphates, which can interfere with calcium absorption when combined with calcium.

Under normal conditions, the calcium to phosphorus ratio in the human body is 2:1. However, excessive consumption of foods high in phosphorus, such as carbonated drinks, cola, coffee, hamburgers, pizza, animal liver, and french fries, can increase the calcium to phosphorus ratio to 1:10 to 20. This excess phosphorus can drive calcium out of the body. Additionally, excessive salt intake can affect the absorption of calcium and may lead to increased calcium loss from the bones. This is because salt contains sodium, and the kidneys need to excrete excess sodium daily. For every 1000 milligrams of sodium excreted, 26 milligrams of calcium are lost. Therefore, a diet that is light and not too salty is recommended during calcium supplementation.