Final answer:
Calcium is essential for bone health, muscle function, and nerve signaling, with adults requiring 800 mg/day and higher amounts for pregnant women and children. Dairy products and leafy vegetables are rich in calcium, and vitamin D is necessary for proper absorption.
Step-by-step explanation:
Calcium is critical for bone development and strength, as it's the most abundant mineral in the human body and plays a fundamental role in bone mineralization and tooth health. An adequate intake of calcium is also vital for maintaining a stable nervous system, ensuring a normal and strong heartbeat, aiding in blood clotting, and regulating nerve impulse conduction. For average adults after the age of 18, the recommended daily requirement is 800 mg/day, while lactating and pregnant women in their second and third trimesters need 1.2 gm/day. Infants under 1 year require 360-540 mg/day and children between 1-18 years need 800-1200 mg/day.
Dietary sources of calcium include milk (0.2 gm/100 ml), cheese, orange juice, broccoli, and sardines. Other good sources are egg yolk, lentils, nuts, cabbage, cauliflower, and asparagus. For calcium absorption, the presence of vitamin D is essential, as it helps the small intestine absorb calcium more effectively.
It is especially important for adolescents and young adults to ensure they consume enough calcium, as 60% of bone density is formed during this period. Young females, in particular, need to be mindful of their calcium intake since they are at higher risk of developing bone density issues due to typically lower calcium consumption.