Calcium is an essential mineral, in other words, we really do need it in our diet. This is because it is the primary component of our bones and teeth (this is where 99% of our body's calcium is found). The remaining 1% of calcium is used for nerve conduction, muscle function, blood clotting and for heart function. Due to the importance of this mineral in our body, it is essential that we strive to get enough of it in our diet. Most people are fairly aware that dairy is a great source of calcium but what about those that don't consume dairy? Can they get sufficient dietary calcium?
Is dairy the only source of dietary calcium?
No, dairy is not the only source of calcium in our diet. That being said, it is one of the best sources of calcium, in terms of concentration and ease of absorption. By consuming milk and other dairy products, you don’t have to work very hard to obtain the recommended amount of calcium each day. All you need is about 3 daily servings to accomplish this which is fairly easy for most people to do. In fact, about 75% of the calcium obtained in the typical North American diet is from dairy.
Despite the ease at which dairy provides calcium, there are a number of reasons why people may not consume dairy such as an allergy, for ethical reasons or simply a taste preference. For those individuals, calcium must be obtained through alternative sources, of which there are plenty (that's good news!).
What about calcium absorption?
When talking about calcium, it's important to be aware of its bioavailability. What’s this bioavailability, you ask?
Essentially it’s the amount of nutrient that is actually absorbed, or available for absorption in your digestive tract. There is often a portion of a nutrient that, even though ingested, won’t get absorbed. This could be due to something like an local environmental factor (like the pH of your digestive tract) or the presence of other foods in the digestive tract that either directly inhibit or compete for absorption. This bioavailability is sometimes referred to as the fractional absorption (as in the fraction that is absorbed) and this value can vary quite a bit. In dairy, the fractional absorption is about 30% while in spinach it is about 5%.
A few things can decrease the bioavailability of the calcium found in food. Among them are components of foods called oxalates and phytates which are found in various plant foods. These components can either be in the foods themselves or from other foods present in the digestive tract. In the case of spinach, this lower percentage of absorbed calcium is due to its high oxalate content. This means that even though spinach has a relatively high calcium content (~115 mg calcium in ½ cup cooked), only about 6 mg is absorbed.
So, does this mean that you’re hooped if you don’t want to (or can’t) consume dairy? No, not really. There are a number of non-dairy calcium sources that can help you achieve an adequate amount of dietary calcium. That’s exactly what I’m here to talk about.
How much calcium do you need?
Before we get into talking about non-dairy sources of calcium, I thought it would be wise to talk to briefly about our calcium needs.
When assessing our body's need for any nutrient, experts take into consideration our biological need, amount excreted (i.e. lost through urine, feces, sweat) and our body’s ability to absorb the nutrient.
As we've already learned, not all the calcium we consume is absorbed. It is assumed that, on average, about 30% of dietary calcium is absorbed. This means that even though the recommended intake for calcium is 1000 mg (for an adult), it is assumed that not all of the 1000 mg will be absorbed. It is set a little higher to make up for the bioavailability. What's important is to have an idea of which non-dairy foods are good sources of available calcium and to include those foods routinely in the diet. This next section will help you accomplish this.
Let's talk non-dairy sources of calcium...
The good news, if you don't consume dairy, is that there are plenty of non-dairy sources of calcium available to you. The not-so-good news is that you really do need to make it a priority and have some idea of what those better sources of non-dairy calcium are.
Below is a table of non-dairy calcium sources. This table includes the amount of calcium actually absorbed based on fractional absorption studies (in the far right column). Milk is included for comparison.
A calcium-rich, dairy-free meal plan...
Below is an example meal plan that satisfies calcium requirements without including dairy (calcium sources in italics). Please note that this meal plan is only to show non-dairy calcium sources, and is not a complete meal plan. If you need help meal planning, please see a Registered Dietitian for an individualized plan.
1 cup calcium fortified soy milk
2 Scrambled eggs
1 slice of bread
Morning snack: 2-3 dried figs and an apple.
½ can of salmon (with bones) OR ½ cup edamame
Green salad - includes ½ cup baby kale leaves
1 cup calcium fortified almond milk
Afternoon snack: ¼ cup almonds and pear
Tofu (3 oz) stirfry including with 1 cup bok choy and ½ cup broccoli
Total calcium: 1384 mg (with salmon) OR 1195 mg (with edamame). This amount is slightly higher than the 1000 mg recommended for adults (19-50 years). Don't worry too much if you're over a bit one day, as you may be slightly under another day. We are really looking to average out to around 1000 mg calcium each day.
Curious about your own calcium intake? Check out these online calcium calculators to get an idea of how you are doing in the calcium department. For a estimate of using a daily intake click here and for weekly click here.
Other factors that influence calcium...
While making sure that you get enough calcium each day is important, there are other things you can do to help your body better obtain or absorb dietary calcium, including:
Get enough vitamin D
Vitamin D directly helps with the absorption of calcium.
Choose foods high in vitamin D every day such as vitamin D fortified milks and yogurts, eggs yolks, salmon, sardines, and herring.
Talk to a dietitian if you think your diet may be inadequate in vitamin D, as you may benefit from a supplement.
Limit sodium intake
A diet high in sodium/salt causes the body to excrete more calcium.
For tips on how to choose low sodium foods, read Salt: Is it a little or a lot?
There is evidence that eating large amounts of animal protein will increase excretion of urinary calcium, however, the same is true of certain types of plant proteins. Studies do show that ensuring you have enough dietary calcium and eating plenty of fruits and veggies can offset any additional loss of urinary calcium from protein intake.
If you rely on fortified milk alternatives (soy, almond, rice, etc.) to meet your calcium requirement, remember to shake the container before your pour yourself a glass. The added calcium tends to sink to the bottom which means that you may not be getting the calcium that you think. So shake, shake, shake before you drink.
As you can see, there are some great sources of non-dairy calcium and some not-so-great sources. Being aware of dietary factors and food components that inhibit and promote calcium absorption is key.
In my professional opinion, the best (and easiest) way to ensure adequate calcium intake without dairy is to include a serving (or better yet, two or three) of fortified milk alternative each day. In addition to this, I encourage including calcium-rich (and calcium-available) foods each day such as calcium-set tofu, salmon, sardines, choy sum or bok choy. Take another look at the table of non-dairy calcium foods (above), are you having foods from the top third of this list often? If not, it’s time to start and up your calcium game.
To answer the question whether or not you can satisfy your calcium needs without dairy, the answer is absolutely! You don’t exactly need dairy foods to meet your calcium requirements. Including dairy is an easy way to get your calcium needs met but with some knowledge and meal planning, you can ensure your body gets the calcium it needs without dairy products.