How do our bodies absorb calcium?
Our bodies absorb calcium differently according to age, sex, and body needs. 60% of calcium intake is absorbed in infants and children as they need more calcium to build their bodies. In adults, the body only absorbs 20% of calcium intake as their body doesn’t grow as much as children, and this percentage decreases with age.
Multiple factors affect calcium absorption as:
It plays a significant role in calcium absorption, as it encourages intestinal cells to absorb more calcium. Vitamin D affects calcium deposition in bones. Thus, the levels of the vitamin should be normal to protect against or treat calcium deficiency. Sun is a natural source of vitamin D, especially midday, and that will help with elevating vitamin D levels, which will increase calcium absorption.
Magnesium also helps in calcium absorption and deposition in bone. The body needs 310 mg daily from magnesium.
• Coffee and tea
Avoid drinking coffee and tea after meals as they contain tannic acid. Tannic acid combines with calcium, forming a complex which interfere with calcium absorption.
• Plant-based food
Calcium intake can be found in plants, as in beans, nuts, and seeds. They contain phytic acid and oxalic acid, which interfere with calcium absorption.
Supplements and food rich in iron should be taken separately from food rich in calcium because they are absorbed from the same cells. Thus, consuming them together will create competition between iron and calcium, which decreases both of their absorptions.
• Digestive system
The digestive system is responsible for nutrient absorption. Gut health should be monitored so the body can benefit from the ingested food. Any GIT diseases may affect the absorption of calcium.
• Parathyroid gland
It secretes a hormone called parathyroid hormone (PTH) with a similar action than vitamin D on the absorption of calcium. The parathyroid hormone decreases the excretion of calcium in the urine and its absorption in the intestine, and increases calcium mobilization in bone tissue. If levels of parathyroid hormone increase, this will lead to calcium deficiency.