Every time I tell someone I’m in nutrition, I get a question or comment about food, the latest diet craze, or my favorite nutrition habits. I realized that for every person that does ask me a question, there are a lot more who are wanting to know the same thing, but were too afraid to ask.
In this new series (as of yet unnamed), I’ll be answering the most frequently-asked questions I receive about nutrition as well as your questions! Have something you’d like to see me write about? Email me at samantha.attard[at]gmail.com!
Today’s Question: What are the best dietary sources of calcium?
If I was to ask a group of people what the best dietary source of calcium is, undoubtably most people would answer – Milk! This unanimous uproar of support is a product of the truly amazing marketing campaigns from the Dairy Council over the last few decades. However, as Michele Simon and Andy Bellatti point out in their report, dairy products like milk are not the only dietary sources of calcium.
But is dairy the best source of calcium?
Calcium is found in a variety of plant- and animal-based foods including milk, cheese, kale, broccoli, almonds, black beans, sardines, and bok choy. Per serving, milk and dairy products have some of the highest levels of calcium, but the plant-based sources are not far behind, and particularly with a varied diet, it is possible to match the calcium levels of dairy foods while still eating a dairy-free.
There are a few important points we have to consider if we’re trying to find the best dietary sources of calcium:
1. Calcium absorption is more efficient and lower calcium intake levels.
2. Calcium absorption in the intestinal lumen requires adequate Vitamin D; Magnesium is required to adequately store calcium in bones rather than soft tissues.
3. Some calcium in plant-based sources is less bioavailable because the calcium is bound to oxalate and phytate.
Let’s investigate these points further to figure out the best ways to meet the recommended daily allowance (RDA) for calcium.
This means that a smaller percentage of calcium is absorbed if you take a single 1000mg supplement compared to taking a 500mg supplement at two different times of day.
Thus, choosing a food with the highest amount of calcium on the label (like milk or dairy products), may not be the most efficient way of getting your calcium fix. Instead, multiple lower-calcium foods consumed throughout the day can allow for more efficient absorption of the calcium you are ingesting.
If there is one thing for sure in nutrition, it’s that the chemicals swirling through our bodies are highly regulated and are interrelated. Vitamin D is necessary for proper absorption of calcium into your blood stream. Magnesium, on the other hand, is responsible for getting the calcium you ingest into hard tissues like bone, instead of staying in your blood stream or in soft tissues like your arteries (where too much calcification is a bad thing). In fact, supplementing with magnesium versus calcium may be the best way to improve your calcium status.
It’s also important to note that vitamin D is a fat-soluble vitamin, so eating fat at the same time as you ingest your vitamin D and calcium is needed for good absorption. Thus, drinking skim milk or no-fat yogurt for their calcium content might not result in the highest absorption levels. Conversely, beans, nuts, and grains all have fat naturally, and we often consume these foods in mixed dishes that do have olive oil or other fat-containing foods.
And where do we get the most magnesium? Plant-based foods like almonds, cashews, soymilk/edamame, black beans, and seaweeds. More info on magnesium-rich foods can be found here.
Thus, eating foods high in calcium AND magnesium (which, you may recall, are the plant-based sources of calcium) may be the best way to improve your calcium status.
Which brings us to an important point…
3. To get the most out of your plant-based sources of calcium and magnesium, they need to be properly prepared.