Oman today_ Calcium is one of the most important minerals for the body, playing a crucial role not only in strengthening bones and teeth but also in various metabolic processes, including muscle contractions and cell signaling. To optimize calcium absorption, several factors, including Vitamin D, must be considered, as these two minerals work together in the body. Increasing Vitamin D levels enhances calcium absorption, making it recommended to consume both simultaneously, whether through supplements or food sources.
Calcium Needs at Different Stages of Life
Calcium requirements vary by age and gender. For children aged 1 to 8 years, around 700 to 1000 mg of calcium (equivalent to 2 to 3 cups of milk or yogurt) is recommended daily. Children over 9 years old and teenagers need 1300 mg of calcium daily. Adults aged 19 to 50 require 1000 mg, while women aged 51 to 70 need 1200 mg of calcium daily.
Interestingly, the absorption of calcium from different food sources varies. On average, 30% of the calcium in dairy products and supplements is absorbed, but calcium from kale is absorbed at a rate of 50-60%.
Factors Affecting Calcium Absorption
Several factors can influence calcium absorption. One of them is phosphorus deficiency, often caused by the use of acid-reducing medications like aluminum-magnesium antacids, which can reduce calcium absorption. Additionally, a high-fat diet reduces calcium absorption in the intestines. During pregnancy, breastfeeding, and infancy, calcium absorption increases, but it decreases with age, especially after middle age.
Animal-based proteins, particularly meat, can increase calcium excretion through urine. Furthermore, calcium is better absorbed in an acidic stomach environment, so consuming calcium-rich foods with meals can enhance absorption. People with achlorhydria (reduced stomach acid secretion) or those taking antacids may face challenges in calcium absorption and, over time, become more susceptible to osteoporosis.
Barriers to Calcium Absorption
Certain substances, such as oxalates and phytic acid, can hinder calcium absorption. Oxalates are found in foods like spinach, beets, rhubarb, and cocoa, while phytic acid is present in grains and seeds. Increased sodium and caffeine intake are also factors that reduce calcium absorption. Additionally, carbonated soft drinks containing phosphoric acid can prevent calcium from being absorbed into bone cells.
Excessive consumption of acidic foods, such as pickles and sour foods, can lower blood pH. Under normal circumstances, blood pH is neutral, but consuming too many acidic foods increases blood acidity. In response, the body releases calcium from bones to balance the pH, potentially leading to osteoporosis in the long run.
Medications that Reduce Calcium Absorption
Certain medications can interfere with calcium absorption. Antibiotics like ciprofloxacin and tetracycline, non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and indomethacin, and anticonvulsants like phenobarbital can all affect calcium absorption. Diuretics like furosemide (Lasix) and corticosteroids can also decrease calcium absorption and increase its excretion from the body.
Important Tips for Calcium Consumption
To optimize calcium absorption, it is essential to maintain a time gap between taking antacid medications and calcium-rich foods or supplements. Adequate Vitamin D intake (15 mcg/day for individuals under 70 years and 20 mcg/day for those over 70) is also crucial for improving calcium absorption. However, simply consuming calcium is not enough to ensure bone health. It is important to consider factors like physical activity, proper nutrition, and avoiding food and drug interactions that may hinder calcium absorption.
Finally, rich sources of calcium include low-fat dairy products, soy and its derivatives, kale, nuts, and fish with bones. For optimal calcium absorption, it is recommended to choose low-fat dairy products.
To maintain bone health and prevent problems associated with calcium deficiency, it is vital to ensure proper and balanced calcium intake. Additionally, one should avoid food and drug interactions that reduce calcium absorption and follow a suitable diet rich in calcium and Vitamin D.