The Importance of Calcium
Calcium is a vital mineral essential for many of the body's functions, far beyond just building and maintaining strong bones and teeth. It plays a critical role in nerve function, muscle contraction, and maintaining a regular heartbeat. When the body doesn't receive enough calcium from food, it draws the mineral from your bones to maintain stable blood levels, which can lead to weakened bones and, over time, conditions like osteopenia and osteoporosis. Recognizing what to eat if your calcium is low is the most effective and safest way to address a dietary shortfall.
Dairy and Fortified Calcium Sources
For many, dairy products are the most well-known source of calcium. They are typically rich in the mineral and are generally well-absorbed by the body.
Dairy Products
- Milk: An excellent source, with one cup providing around 300 mg of calcium.
- Yogurt: Low-fat plain yogurt contains about 310 mg per 6 ounces, while Greek yogurt offers around 200 mg.
- Cheese: Ricotta, mozzarella, and cheddar are all good options. Four ounces of ricotta can provide 335 mg of calcium.
Fortified Products
Many common foods and beverages are fortified with calcium and offer a significant boost to your daily intake. Always check the nutrition label, as the fortification levels can vary by brand.
- Fortified Plant-Based Milks: Soy, almond, and oat milks are often fortified to contain similar calcium levels to dairy milk.
- Fortified Orange Juice: A single cup of fortified orange juice can supply a significant amount of calcium.
- Cereals and Breads: Many breakfast cereals and breads made with fortified flour contain added calcium.
Non-Dairy and Plant-Based Calcium
For those who are lactose intolerant, have a milk allergy, or follow a vegan diet, there are many excellent non-dairy sources of calcium.
Vegetables and Legumes
- Leafy Greens: Collard greens and kale are standout sources, offering highly bioavailable calcium. A cup of cooked collard greens can provide 266 mg, while cooked kale contains around 179 mg per cup. However, be mindful that greens like spinach are high in oxalates, which can hinder absorption.
- Bok Choy: This Chinese cabbage is a good source of absorbable calcium.
- Tofu: Tofu that has been prepared with a calcium salt (calcium sulfate) is a powerhouse of calcium, with some brands providing more than 800 mg per serving.
- Beans: Canned baked beans and navy beans contain good amounts of calcium.
Nuts and Seeds
- Almonds: Just one ounce of almonds contains about 76 mg of calcium, plus healthy fats and protein.
- Sesame Seeds and Tahini: A tablespoon of tahini can provide a significant calcium boost.
- Chia Seeds: One ounce of chia seeds offers approximately 179 mg of calcium.
Fish
- Canned Sardines and Salmon: When eaten with the bones, canned sardines and salmon are an excellent source of dietary calcium.
Maximizing Calcium Absorption
Consuming calcium-rich foods is only half the battle; your body also needs to absorb it effectively. Several nutrients and dietary habits can help improve absorption.
- Get enough Vitamin D: Your body needs Vitamin D to absorb calcium properly. Sources include fortified foods, fatty fish, egg yolks, and safe sun exposure.
- Combine Calcium with Meals: For better absorption, many calcium supplements, particularly calcium carbonate, should be taken with meals.
- Spread Intake Throughout the Day: For optimal absorption, it's best to consume calcium in smaller doses (500-600 mg or less) several times a day rather than all at once.
- Limit Salt and Caffeine: High salt intake and excessive caffeine consumption can increase calcium excretion from the body.
Food vs. Supplements
While supplements are an option, most health professionals agree that obtaining calcium from food is the ideal approach. Foods provide a host of other beneficial nutrients that work synergistically to support overall health. They also allow for a more gradual, sustained release of calcium into the body, which is thought to be more beneficial. Supplements may be necessary for some individuals, but should be discussed with a doctor, as excessive intake can cause issues.
| Feature | Dietary Calcium (Food) | Calcium Supplements |
|---|---|---|
| Absorption Rate | Absorbed gradually throughout the day, often more efficiently with other nutrients. | Can be absorbed quickly, but in larger doses (over 500-600 mg) absorption is less efficient. |
| Additional Nutrients | Provides a variety of vitamins, minerals (like Vitamin D and K), and protein. | Provides calcium in a concentrated dose, but lacks other beneficial nutrients. |
| Convenience | Requires careful meal planning to ensure adequate intake. | Easy to take as a pill; a practical solution for busy lifestyles or specific dietary restrictions. |
| Potential Risks | Very low risk of excessive intake and associated complications like kidney stones. | Higher risk of excessive intake if not monitored, which can lead to side effects like bloating, constipation, and rarely, more serious health issues. |
Conclusion
Addressing low calcium levels involves a proactive and informed dietary approach. By focusing on a variety of calcium-rich foods—including dairy products, fortified alternatives, and a wide array of plant-based options—you can effectively boost your intake. For those with dietary restrictions, excellent non-dairy sources like calcium-set tofu, leafy greens, and seeds make it simple to meet nutritional needs. Remember to optimize absorption by including Vitamin D and spreading your intake throughout the day. While supplements can be a helpful tool, the focus should always be on a balanced diet rich in whole foods. Consult a healthcare provider or registered dietitian for personalized advice, especially if you suspect a significant deficiency or are considering supplements. For more information on bone health, consider visiting the NIH Office of Dietary Supplements.
