Calcium Controversy: Do You Need Dairy or Supplements to Meet Your Daily Requirements?

Calcium is essential, but most people don’t get enough. One reason for this is that people don’t like or have access to calcium-rich foods; another is because of lactose intolerance, which affects over 1/3 of people in the U.S. When you consider that dairy products like yogurt and cheese have the highest amount of calcium in them (around 300-400 mg per serving), you might start to worry about how to get enough calcium in your diet when you give up dairy. Many doctors recommend calcium supplements to lactose-intolerant patients to help meet their needs. But is buying another supplement the best way to get your daily calcium? Can we achieve our daily recommended calcium intake with non-dairy, budget-friendly, whole-food sources without needing to purchase another supplement?

Decoding Calcium

We need calcium to keep our bones and teeth healthy. With so many bones needed to stay healthy, we have more calcium in our bodies than any other nutrient, so it's important to ensure we meet our daily requirements. Poor calcium intake can lead to fragile bones, increased risk of falling, and, eventually, osteoporosis. Depending on your age, gender, and health status, the daily recommended intake of calcium is anywhere between 1000-1300 mg per day. Calcium needs stay pretty consistent in men as they age. For women, however, calcium requirements increase with age due to decreased estrogen production at the start of menopause. You can see your recommended calcium intake in the chart from the Office of Dietary Supplements below.

CALCIUM RECOMMENDATIONS BASED ON AGE:

IMAGE CREDIT: Calcium. Nih.gov. Updated January 23, 2024. Accessed May 11, 2024. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/

Two Peas in A Pod

When we think about calcium, we also want to be aware of our vitamin D intake. Vitamin D is required for our gut to absorb calcium. Without it, we won’t use much of that calcium from our food or supplements. Vitamin D is also necessary to maintain blood calcium levels through its role in bone health. There are only a limited number of foods you can take in that will have vitamin D in them, such as fortified milk, cereals, and juices, as well as meat, fish, and poultry. The best way to get vitamin D into the body is through sunlight, at least 15 minutes at a time. If you are not in an area where you can get regular sunlight, this is one supplement you may need to incorporate.

Behind the Calcium Curtain

So now we know how much calcium we need and that we need vitamin D to absorb our calcium. What are the other conditions for achieving our daily requirements of calcium intake? Knowing that our bodies can only absorb up to 500 mg of calcium at one time is essential. So, loading up on all of your calcium at one meal or in a single supplement won’t get you very far, either. Calcium absorption is also decreased by phytic and oxalic acid in foods, alcohol, and caffeine. No need to avoid alcohol and caffeine altogether, but you might want to wait about an hour or two after your meal before you reach for either.

Phytic and oxalic acids are compounds in plants that form indigestible salts with calcium. Since these salts cannot be digested, they block calcium from being absorbed by the gut. As a result, certain plant foods with high levels of these acids have a lower rate of calcium absorption than foods without. For example, only 5% of the calcium in spinach is absorbed, whereas the calcium in milk has around a 27% absorption rate. Other foods with high levels of oxalic acid are collard greens, sweet potatoes, rhubarb, and beans. Though foods containing these acids tend to be plant foods, not all plant foods contain these compounds. Broccoli, kale, and cabbage have a similar rate of absorption to that of milk, although the amount of calcium per serving is much lower. See below for non-dairy, calcium-rich foods:

NON-DAIRY, CALCIUM-RICH FOODS:

Final Recommendations

There is no need to let the idea of phytic and oxalic acids get you down. In fact, the interactions between calcium and oxalic or phytic acids have little effect when you eat a variety of plant foods. It is still possible to get your daily recommended intake of calcium through foods without relying on dairy or an expensive supplement. In general, aim for the following tips:

→ Aim for no more than 500 mg at a time

→ Make sure you’re getting enough vitamin D

→ Avoid drinking coffee or alcohol with your calcium-rich foods

→ Eat a variety of calcium-rich, plant foods daily

About the author: Noelle McBride is a Master’s candidate at Bastyr University in Kenmore, WA. Before entering her Master’s program, she graduated from Indiana University Northwest with a Bachelor’s degree in Psychology and Neuroscience. 

References:

1. Calcium. Nih.gov. Updated January 23, 2024. Accessed May 11, 2024. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
2. ‌Vitamin D. Nih.gov. Updated November 8, 2022. Accessed May 11, 2024. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
3. Lactose Intolerance. Nih.gov. Updated February 2018. Accessed May 11, 2024. https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance