A Scientific Guide to Calcium Supplementation for All Ages: Diagnosis and Contraindications of Calcium Deficiency in Children, Calcium Supplementation Strategies for the Elderly, and Clarification of Misconceptions about Bone Hyperplasia

Because children grow rapidly and have little outdoor activity and sun exposure, they often experience insufficient calcium absorption, leading to various symptoms of calcium deficiency. A child's calcium deficiency can be assessed from the following aspects: (1) Excessive sweating, unrelated to temperature, especially head sweating after falling asleep, causing the child's head to constantly rub against the pillow, eventually resulting in a bald patch on the back of the head. (2) Irritability and lack of interest in the surrounding environment; parents may notice the child is less active than before. (3) Night terrors, often waking suddenly at night and crying incessantly. (4) Delayed teething in children over 1 year old; some children still have no teeth at 18 months, and delayed closure of the anterior fontanelle, often remaining open after 18 months. (5) High forehead, forming a square head. (6) Frequent beaded ribs, due to vitamin D deficiency, causing costal cartilage hyperplasia; the cartilage of each rib connects like beads, often compressing the lungs, causing poor ventilation and making the child prone to bronchitis and pneumonia. In severe cases of calcium deficiency, muscles and tendons become lax. If the abdominal and intestinal muscles are relaxed, gas can accumulate in the intestinal cavity, causing the abdomen to swell like a frog's belly. If the tendons of the spine are relaxed, kyphosis (hunchback) can occur. After a child is one year old and learning to walk, calcium deficiency can cause osteomalacia, causing the lower limbs to bend when standing due to body weight. This can manifest as "X"-shaped legs or "O"-shaped legs, and increases the risk of fractures. The symptoms of calcium deficiency vary, and parents should learn to identify these symptoms to ensure their child is calcium deficient. If deficiency is present, provide calcium-rich foods such as fish, dried shrimp, kelp, and pork rib soup. Also, include plenty of vitamin D-rich foods such as pork liver, lamb liver, and beef liver to promote calcium absorption. Generally, mild calcium deficiency symptoms can improve with dietary supplementation. For more severe symptoms, vitamin D and calcium supplements may be necessary under the guidance of a doctor.

Children need a proper supplement of nutrients for growth and development. Among various inorganic salts, iron, zinc, and calcium are most easily deficient. Therefore, some parents often buy calcium powder and calcium tablets for their children. But do all children need calcium supplements? Dairy products and seafood are rich in calcium. Every 100 grams of milk contains 102 milligrams of calcium, and 500 milliliters of milk can meet the daily requirement of children under 3 years old. The calcium absorption rate of breast milk is better than that of raw milk, so breastfed babies are less likely to be calcium deficient. Shrimp shells, kelp, and fish bone meal in aquatic products are all good sources of calcium. Every 100 grams of shrimp shells contains as much as 1760 milligrams of calcium. Soybeans also contain a lot of calcium, but their skin contains a lot of phytic acid, which can hinder calcium absorption. Removing the skin greatly increases the absorption rate. Some vegetables, such as spinach, are also rich in calcium. If they are blanched and then stir-fried to remove some of the oxalic acid, they are also a good source of calcium. Vitamin D can greatly promote calcium absorption. Simply supplementing with calcium without vitamin D will not prevent rickets. Generally speaking, children over two years old spend more time outdoors, and their skin synthesizes vitamin D after being exposed to sunlight for the body to use. Furthermore, at this age, the variety of foods available increases, making calcium and vitamin D sources more abundant. Simultaneously, their growth rate slows down, so rickets is very rare, and additional calcium supplementation is generally unnecessary. Isotope studies show that excess calcium in the intestines is excreted in feces, not only wasting it but also hindering the absorption of iron and zinc, leading to anemia and loss of appetite. This is because iron, zinc, and calcium are all divalent cations, and they antagonize each other during intestinal absorption. Therefore, children should not be blindly given large amounts of calcium supplements.

Due to varying physical conditions, the functions of different organs decline to varying degrees among the elderly, and their digestive capacity also weakens. To ensure the body's nutritional needs are met, it is essential to consume easily digestible and absorbable foods. The elderly are particularly prone to osteoporosis and should supplement with sufficient calcium and vitamin D to reduce bone calcium loss, prevent osteomalacia, and avoid age-related fractures. So how should the elderly choose calcium-rich foods? Foods rich in calcium include milk, tofu, soy milk, sesame seeds, spinach, lentils, and edamame, with 100 grams containing approximately 120 mg, 177 mg, 75 mg, 564 mg, 103 mg, 110 mg, and 100 mg of calcium respectively. However, while plant-based vegetables such as spinach and edamame contain a significant amount of calcium, they also contain a high amount of oxalic acid. Oxalic acid easily combines with calcium to form poorly absorbed oxalates, which cannot be utilized by the body, thus failing to achieve the purpose of calcium supplementation. The elderly can drink a fixed amount of milk daily and eat a small amount of tofu, as well as sesame paste and lentils. It's advisable to avoid consuming the above-mentioned foods with foods high in oxalic acid, as this can reduce calcium absorption. For example, avoid eating spinach or edamame while drinking milk, and don't cook spinach and tofu together. Given the current dietary structure in my country, the calcium intake from food generally doesn't meet the standard requirements, so appropriate calcium supplementation may be necessary. Calcium supplements should be high in calcium and easily absorbed, such as Jingxiang brand pearl calcium. Generally, taking 3 capsules daily provides 360 mg of calcium. Older adults, with reduced digestive and absorption abilities, may need to take more; 6 capsules three times a day will provide better calcium supplementation.

Osteophytes, also known as bone spurs, are a common chronic joint condition that occurs in middle-aged and older adults, affecting many elderly people. It is now recognized that middle-aged and elderly individuals, especially postmenopausal women, are prone to osteoporosis. Therefore, some advocate for appropriate calcium supplementation to improve abnormal calcium and phosphorus metabolism. However, many people worry that since bone spurs are growths at the joints, calcium supplementation might worsen the condition. Calcium is an essential substance in bone metabolism. In infancy, insufficient calcium intake due to vitamin D deficiency can lead to rickets. In middle age, decreased estrogen secretion and abnormal metabolic processes cause bones to become less dense and more brittle, making elderly women highly susceptible to fractures, especially in the legs and arms. Therefore, it is now recommended that these individuals supplement with calcium and increase physical activity to improve osteoporosis. So-called bone spurs are actually related to osteoporosis, but are not caused by excessive calcium intake. After years of work and life, the bones of the elderly undergo degenerative changes, with the soft muscles around the joints being the first to show discoloration and softening. During joint movement, these muscles are easily worn down, eventually fracturing and even detaching at points of greatest pressure, directly exposing the muscle tissue. This exposed muscle tissue becomes very smooth due to constant friction, while other areas, receiving less friction, develop thickened and proliferating cartilage rings at the edges of the soft muscles, joint capsules, and ligament attachments, eventually ossifying. This is what we call bone spurs. Bone spurs are a common condition among middle-aged and elderly people, causing joint pain, limited movement, and in some cases, nerve compression symptoms, bringing pain and inconvenience. Some people with bone spurs are asymptomatic and require X-ray examination for detection. Therefore, bone spurs are not necessarily caused by excessive bone proliferation, but are related to the process of osteoporosis. Appropriate calcium supplementation can improve abnormal bone metabolism in the elderly and help prevent bone spur formation. Middle-aged and elderly people who supplement calcium under the guidance of a doctor have no need to worry about aggravating bone spur formation.