When people think of calcium, they probably picture a large glass of milk. While milk is an excellent source of calcium, yogurt, tofu, canned fish, and fortified plant-based milks are also rich in calcium. Surprisingly, even leafy green vegetables and broccoli contain small amounts of calcium in their diet. However, if you don’t get enough of these calcium-rich foods, your doctor may recommend calcium supplements to meet your daily needs and maintain bone health.
According to Kristen Hruszak, a registered dietitian and founder of Nutrition for Seniors, adequate daily calcium intake not only strengthens bones and teeth but also plays a vital role in blood clotting, muscle contraction, heart rate regulation, and nervous system function. She explains that most calcium is stored in bones, and the body constantly uses and replenishes its calcium stores to support these important functions and maintain balance. Fortunately, you can help replenish your calcium stores by adjusting your diet and taking calcium supplements. However, timing your calcium supplements is crucial for maximum effectiveness. Read on to learn how to maximize the absorption of calcium supplements.
As we age, our body’s ability to absorb calcium gradually declines. Grushak explains that intestinal calcium absorption largely depends on the presence of active vitamin D, calcitriol. The kidneys play a crucial role in converting vitamin D to calcitriol. However, with age, the efficiency of conversion in the kidneys can decrease, leading to decreased calcium absorption and an increased risk of bone loss. Therefore, older adults need to consume more calcium than other groups of adults to prevent calcium deficiency and maintain bone health.
During menopause, estrogen levels decline, negatively impacting bone health. Estrogen plays a crucial role in maintaining bone density and strength by promoting calcium absorption, bone formation, and preventing bone resorption. A decrease in estrogen levels can lead to bone loss and increase the risk of osteoporosis. If you are perimenopausal or menopausal, make sure you are getting enough calcium from your diet.
A wide variety of calcium supplements in various forms are available on store shelves. The most common include calcium carbonate, calcium citrate, calcium gluconate, and calcium lactate. Khrushchak claims that of these options, calcium citrate, calcium lactate, and calcium gluconate are more easily absorbed and better tolerated than calcium carbonate.
Taking calcium supplements with food can affect their absorption and effectiveness. Khrushak states that calcium citrate, calcium lactate, and calcium gluconate are easily absorbed at any time of day and can be taken on an empty stomach or with meals. On the other hand, if you take calcium carbonate, it should be taken with or immediately after meals to improve absorption. This may also reduce the likelihood of gastrointestinal side effects such as bloating, flatulence, or constipation.
However, the type of food consumed can also affect calcium absorption. For example, phytates, plant compounds found in bran, nuts, whole grains, dried beans, and seeds, can bind with calcium, hindering its absorption, explains Hrushak. Similarly, oxalates, found in rhubarb, spinach, nuts, and tea, can have a similar effect. Soaking dried beans and cooking these foods can minimize their effects—or taking calcium supplements separately from foods rich in these ingredients.
Certain medications can also interfere with calcium absorption. In particular, glucocorticoids such as prednisone can reduce calcium absorption. Hrushak states that for optimal absorption, it is generally recommended to take calcium supplements two to four hours apart from these medications. Other medications that can negatively interact with calcium supplements include lithium, quinolone antibiotics, dolutegravir, and levothyroxine. If you take calcium supplements and any of the medications mentioned above, consult your doctor to determine whether your blood calcium levels need to be monitored.
For maximum effectiveness, calcium supplements are best taken with vitamin D, magnesium, and vitamin K. The powerful synergy between vitamin D and calcium is well known—they’re like the stars of the strong-bones movie. Magnesium plays a supporting role, helping activate vitamin D. Vitamin K, which plays an important role, shouldn’t be overlooked either. Vitamin K (especially vitamin K2) activates proteins necessary for bone mineralization. This process also helps prevent vascular calcification, which is closely linked to cardiovascular disease. Adequate dietary intake of vitamin D, magnesium, vitamin K, and calcium can significantly improve bone health and overall well-being.
To maximize the absorption of calcium supplements, Grushak recommends the following:
Don’t take more than 500-600 mg of calcium supplements at a time. Smaller doses are more easily absorbed. Allow at least four hours between doses.
While calcium citrate, calcium lactate, and calcium gluconate are generally well absorbed whether taken with or without food, taking them with vitamin D offers additional benefits. This is because dietary fats in food can enhance vitamin D absorption. The result? Improved calcium absorption.
When taking calcium supplements, you should avoid foods high in oxalic and phytic acids, as well as large amounts of caffeine.
To maximize the effectiveness of calcium supplements, consider the dosage, the foods you consume while taking them, and any other medications you’re taking. While calcium citrate, calcium lactate, and calcium gluconate can be taken on an empty stomach or with meals, and at different times of day, taking them with food, especially foods rich in vitamin D, will ensure maximum effectiveness. Also, ensure you’re getting enough magnesium and vitamin K from your diet. If you take calcium supplements, consult your doctor for recommendations tailored to your individual health needs.
Post time: Dec-31-2025