If you are either following a pescatarian, dairy-free lifestyle or looking to eat less red meat and more plant-based food options, this blog is for you!
Calcium is a mineral that is required for many body functions such as muscle function, nerve impulses and blood clotting. One of the most important functions of calcium, however, is to maintain bone mineral density.
If you have cut down on dairy, your calcium intake and bone health is an area you need to pay special attention to.
Calcium Requirements
Recommendations for calcium vary slightly from country to country, but the average adult between the ages of 19 and 64 requires around 1000 mg of calcium per day. Calcium requirements are higher in certain life stages, such as growth during teenagehood, after menopause, and pregnancy, and might also be partly dependent on genetics. [cite] Your risk of low bone mineral density can in part be determined by nutrigenetics. For instance, some variants of the VDR gene may mean that you will require more calcium than average.
Calcium and your Bones
More than 99 % of the calcium in your body is stored in your bones, and research has shown that not eating enough calcium can increase your risk of hip fractures. Inadequate calcium intake can cause bone mineral loss through a process called resorption. In order to function, your body is very strict about its calcium levels – they have to be maintained at a certain level at all times. If you do not provide your body with enough calcium to maintain these levels your body borrows calcium from your bones. By removing calcium from your bones, they will get weaker, especially if your diet is consistently low in calcium. When we provide our body with enough calcium, on the other hand, those strict calcium levels in your blood are easily maintained and the calcium stays in your bones, keeping them strong and healthy. [cite]
Calcium Food Sources
We all know that dairy is an excellent source of calcium, but even if it is something you do not include in your diet, you can still meet your calcium requirements. Research has estimated that our palaeolithic ancestors may have had up to 1956 mg of calcium per day from non-dairy foods such as green leafy vegetables - that’s twice the current calcium recommendations!
There are two important factors to consider when it comes to calcium sources. Firstly, how much calcium does the food contain? And secondly, how well is that calcium absorbed?
Calcium Bioavailability
Despite popular belief, calcium can also be found in plant-based foods - but it may be more challenging to get all the calcium you need when on this diet. It all comes down to a concept known as bioavailability. Put simply, the bioavailability of a nutrient in food tells us how well that nutrient is absorbed in our body.
Milk for example has around 300 mg of calcium per cup, 30% of which our body actually absorbs. Cooked spinach on the other hand has around 230 mg per cup, but only 5% of that is actually absorbed. This means that we’ll absorb around 100 mg of calcium from a cup of milk, but only 12 mg from one cup of cooked spinach. [cite] [cite]
Why is the absorption so different? Two of the most well-known components of foods that can affect how well calcium is absorbed are oxalates and phytates. These are found in various plant foods that can bind to some of the calcium moving through the gut after a meal, preventing it from being absorbed. The good news is that there are some plant sources along with fish that are full of absorbable calcium, and to make things easier, we’ve made an easy to read table.
Fruit and Vegetables
Kale and Bok Choy get a medium rating in terms of calcium. They both contain a moderate amount of calcium, and are low in phytates and oxalates, so the bioavailability is quite good too. Spinach and rhubarb on the other hand are not a good source of calcium. This is because they are high in phytates and oxalates respectively, so despite both being fairly high in calcium, this calcium is not particularly well absorbed.
Beans and Grains, Nuts and Seeds
The phytates found in beans and grains can affect how well calcium is absorbed. The levels of phytates differ quite a lot between the different types of beans and grains. White beans and kidney beans, for example, are a fairly good source of calcium with a reasonable bioavailability. Nuts and seeds also contain some calcium, but also some phytates, which can affect calcium absorption slightly.
Soy products
Soy milk and tofu are both excellent sources of calcium. This is mostly because of fortification and processing. Part of the process of making tofu often requires calcium for coagulation of the soy curds, resulting in a high calcium end product. Soy milk on the other hand is usually fortified with calcium to give a similar nutritional breakdown to cow’s milk. The calcium found in these soy products is usually very well absorbed because most of the oxalates and phytates are removed during processing.
Fish
Fish itself is not a particularly good source of calcium, but the bones are. Tinned sardines and canned salmon generally still have the bones intact and because they have been softened, they are edible and a wonderful source of calcium with a fairly good bioavailability of around 22 %.
Putting it into Practice
Foods that have very poor calcium absorption such as spinach and rhubarb should not be relied on for calcium. If you are working on improving your calcium intake without dairy, you should only count foods with a calcium fractional bioavailability of 20% or more as a good source of calcium. Using the instructions below can help you meet your requirements:
- Include at least one food high in calcium per day, such as soy milk.
- Eat at least two portions of medium-high calcium foods per day, such as bok choy, kale or beans
- Eat three to four portions of medium-low calcium foods per day such as broccoli, almonds, and sweet potato
To put this into practise, we have created a meal plan example that gives around 1100 mg of calcium per day, which is just above the RDA.
Breakfast: Crunchy toast with almond butter
2 slices whole-grain bread - calcium-enriched (46 mg)
2 Tablespoons almond butter (80 mg)
Snack:
¼ cup raw almonds (88 mg)
Lunch: Hearty bean and vegetable soup
1 cup of kidney beans, cooked (160 mg)
1 cup cooked kale (172 mg)
Vegetables and grains of your choice
Snack: Calcium Green Smoothie
1 cup calcium-fortified soy milk (300 mg)
2 cup raw baby kale (172 mg)
¼ cup sesame seeds (18 mg)
Fruit of choice
Dinner: A rainbow dinner
90 g of sardines/pilchards
1 medium sweet potato (42 mg)
1 cup steamed broccoli (63 mg)
If your nutrigenetic results have revealed that you are lactose intolerant or you are following a vegan lifestyle, you can definitely meet your calcium requirements. It may simply take some extra planning and careful food choices. However, if you have yet to take a test, WHY WAIT! Get a DNAfit test today so you understand your nutrigenetic profile.
