What is bioavailable calcium?

• A. The total calcium content in a food item
• B. The amount of calcium from an ingested dose that the intestine can absorb
• C. The calcium present in dairy products
• D. The amount of calcium lost in urine

Answer: (B)

Bioavailable calcium refers to the amount of calcium from an ingested dose that the intestine can absorb and utilize by the body. It is important in the context of nutrition and health, particularly for bone density and overall skeletal health. The body does not utilize all the calcium that is consumed; some of it is not absorbed due to various factors, including the food matrix, presence of other nutrients, and individual digestive capability.

Option B addresses this concept directly by highlighting the absorption aspect of calcium after ingestion. This means that even if a food item contains significant amounts of calcium, only a fraction may be bioavailable if the body cannot absorb it effectively. Consequently, understanding bioavailable calcium can help in assessing dietary calcium intake and developing nutritional recommendations for individuals, especially those at risk for osteoporosis or other bone health issues.

The other options do not accurately capture the definition of bioavailable calcium. For instance, the total calcium content in a food item does not take into account how much is actually usable by the body, making it less relevant to bioavailability. Similarly, identifying calcium solely in dairy products overlooks the fact that bioavailability can vary across different food sources. Lastly, the amount of calcium lost in urine pertains to calcium excretion rather than the body's ability to absorb calcium