Introduction: Calcium is an essential component for building bones and teeth. During adolescence, bones develop rapidly, requiring a large amount of calcium supplementation. A lack of calcium can slow down growth and affect bone mineral density and skeletal health in adulthood.
Calcium also maintains the normal excitability of muscles and nerves, participates in the blood coagulation process, and plays a significant role in activating various enzymes. Once calcium is deficient, not only the growth of bones and teeth will be affected, but it can also easily lead to rickets in children, osteomalacia in adults, and is detrimental to the normal function of muscles, nerves, the heart, and brain tissue.
Crispy Fried Small Shrimp
I. Physicochemical Properties of Calcium:
Calcium is a silvery-white light metal with an atomic number of 20, a relative atomic mass of 40.078, a melting point of 842°C, a boiling point of 1484°C, and a density of 1.55g/cm³. Calcium is chemically active and can react with water and acids; when heated, it can reduce almost all metal oxides. In nature, it mostly exists in the form of compounds.
II. Factors Affecting Calcium Absorption:
1. Physiological factors: including physiological requirements, nutritional status of vitamin D, calcium, and phosphorus in the body, gastric acid secretion, contact area of the gastrointestinal mucosa, and physical activity;
2. Dietary factors: Calcium intake is the most important factor in the diet affecting calcium absorption rate and total absorption. The calcium absorption rate is negatively correlated with the logarithm of a single calcium intake. When the average daily calcium intake is low or the single calcium intake is reduced, active absorption is activated, thereby increasing the calcium absorption rate;
3. In addition, lactose, oligosaccharides, moderate amounts of protein, and some amino acids can combine with calcium to form soluble complexes, which is beneficial for calcium absorption;
4. A low-phosphorus diet can lower blood phosphorus levels, stimulate the activation of vitamin D, and promote calcium absorption;
5. Oxalic acid and phytic acid in the diet can form precipitates with calcium, reducing calcium absorption;
6. Uronic acid residues in dietary fiber, especially saturated fatty acids, can bind with calcium to form insoluble complexes, thereby reducing calcium absorption;
Clam, Kelp, and Tofu Soup
III. Nutritional Recipes Rich in Calcium:
1. Common foods rich in calcium: Calcium is mainly distributed in milk and dairy products, aquatic products such as shrimp skin and kelp; and in eggs and the bones of poultry and livestock, with both high content and high absorption rates.
2. Plant-based foods, such as green leafy vegetables and legumes, are also important sources of calcium, but their absorption rate by the human body is relatively low;
3. Nutritional Analysis:
① Lentils are rich in calcium and protein; Shiitake mushrooms are rich in amino acids; this dish is nutritious, colorful, and delicious;
② Olive oil is rich in monounsaturated fatty acids, has good heat resistance and a delicate aroma, and has a good effect on lowering blood lipids, making it especially suitable for middle-aged and elderly people;
③ This dish is cooked at a low temperature with less oil and salt, effectively retaining the various nutrients in the vegetables;