Final answer:
The Recommended Daily Allowance of calcium for adults 19 to 50 years old is 800 mg/day. Dairy products and certain vegetables are good sources of calcium, and absorption is influenced by vitamin D and dietary factors. Special groups like pregnant and lactating women require 1.2 grams/day.
Step-by-step explanation:
The Recommended Daily Allowance (RDA) for calcium for adults aged 19 to 50 years old is 800 milligrams (mg) per day. This requirement is crucial for maintaining healthy bones and overall bodily functions. Dairy products like milk, which contains 0.2 grams (gm) of calcium per 100 milliliters (ml), and cheese, as well as vegetables like cabbage, cauliflower, and asparagus, are important dietary sources of calcium. To enhance calcium absorption, it is beneficial to have an acidic pH, adequate vitamin D, and a diet that includes organic acids, lactose, and basic amino acids.
For special groups, such as women during the second and third trimesters of pregnancy and lactation, the requirement increases to 1.2 grams per day. In contrast, infants under one year require 360-540 mg/day, and children aged 1-18 years need 800-1200 mg/day. After age 55 to 60, there is a decline in the intestinal transport of calcium, which can be managed by adequate intake and sometimes supplementation.