I often recommend people supplement electrolytes, especially when first starting a ketogenic diet. However, one of the most common electrolytes often left out of the conversation is calcium.
How to get calcium on keto? Great sources for calcium that are keto-friendly include seeds (poppy, sesame, and chia) cheeses, canned fatty fish WITH bones, almonds, and green leafy vegetables.
Keep reading further to learn what calcium is, why it's essential, signs you may be deficient, and even how much you should be trying to consume.
How To Get Calcium On Keto
When people think of keto and electrolytes, they typically refer to the three most common ones: sodium, potassium, and magnesium. What you may not realize is that calcium is the MOST ABUNDANT mineral in the body.
Calcium is often associated with dairy, and for a good reason. Dairy is, in fact, one of the most abundant sources of calcium there is, but it's not the only source.
Here are five keto-friendly foods that are rich in calcium.
While not technically a “food,” but a category, seeds including poppy, sesame, and chia are chock full of calcium. On average, a single tablespoon of any one of the seeds provides ~126 mg of calcium. 1
A ketogenic staple, cheese is an excellent source of calcium. Out of all cheeses, parmesan cheese has the most calcium. A single ounce serving of parmesan cheese provides 331 mg of calcium.
Canned fatty fish WITH the bones
Aside from being a rich source of omega-3 essential fatty acids, canned fish such as sardines are an excellent source of calcium. Sardines and other fatty fish are also quite the nutritional powerhouses full of high-quality protein and rich in vitamins D and B12.
A four-ounce serving of sardines with their bones provides 85 mg of calcium. 2
Compared to any other nut, almonds are the highest in calcium and also rich in magnesium. Just be careful when including almonds, they are too easy to over-consume.
A single ounce serving of almonds will provide you with 80 mg of calcium.
Now that you know some great sources to get calcium on a keto diet, why is calcium so essential?
Calcium in broccoli and other dark leafy greens like kale are a great way to get more calcium in the diet along with fiber, vitamins, and minerals.
One cup of chopped broccoli will give you 43 mg of calcium, while one cup of chopped kale will provide you with just over 100 mg.
Why Is Calcium Important
Remember how I said calcium is the MOST ABUNDANT mineral in the body? Calcium is the most abundant mineral in your body because it makes up much of your teeth and bones.
Additionally, calcium is quite important when it comes to muscle function. Within the muscle, calcium helps to facilitate the interaction between actin and myosin during contractions. 3
Other roles of calcium 4 :
- Blood clotting
- Nerve impulse
- Regulating heartbeat
- Fluid balance within cells
Ninety-nine percent of the calcium found in your body is located in your teeth and bones, making it essential for the development, growth, and maintenance of them. More importantly, as we age, bone density begins to experience a slow decline. The ingestion of calcium helps to slow, if not prevent, the natural losses we may suffer as part of the aging process.Women should especially be mindful of consuming adequate amounts of calcium since they are more susceptible to osteoporosis. Osteoporosis is a disease in which the density and quality of bone are reduced, leading to a greater risk of fractures.
Signs Of Low Calcium
Hypocalcemia is the term used to describe a calcium deficiency in the medical world. While a keto calcium deficiency isn't as prominent compared to other electrolytes, here are signs and symptoms to look out for:
- Tooth decay
- Bone fractures
- Brittle nails
- Osteopenia or osteoporosis
- Difficulty swallowing
- Muscle cramps (especially in the back and legs)
Certain things may lead to a calcium deficiency:
- Certain genetic factors
- Prescription medications
- Hormonal changes (postmenopausal women and amenorrheic women)
- Malabsorption (Vitamin D, K2, and magnesium can affect calcium absorption)
In general, females are less likely than their male counterparts to consume an adequate amount of calcium from food. 5
How Much Calcium You Need
How much calcium is recommended depends a lot on your age, sex, and even where you live. The calcium RDA for adults ranges from 1,000 mg a day to an upper daily limit of 2,500 mg. On the other hand, the World Health Organization recommends 500 mg per day while in the United Kingdom sets a goal of 700 mg per day.
If you're wondering what a normal calcium level is, according to the National Health and Nutrition Examination Survey (NHANES), mean dietary calcium for males ranged between 871 to 1,266 mg per day. Females, the mean intake was 748 to 968 mg of calcium per day. 6
The amount of calcium we can absorb is affected by the following:
- Amount consumed: As calcium intake increases, the efficiency of absorption decreases. 7
- Components in food: Oxalic acid and phytic acid, found naturally in plants, can bind to calcium and inhibit absorption. 8
- Age and life stage: Calcium absorption is highest in infants and young children, which makes sense due to an increased demand for growing bones. At the other end, absorption decreases nearly 20% in adulthood and will continue to decrease as you age. 9
Furthermore, calcium and vitamin D are closely tied together. Vitamin D increases the rate at which calcium is absorbed into your blood. Without enough vitamin D, your body may not be able to absorb enough calcium from the diet.
Vitamin D can be obtained in three ways:
- Sunlight exposure
Some keto-friendly sources of vitamin D include egg yolks, saltwater fish, and liver. The RDA for vitamin D is 600 international units a day for most adults.
What About Calcium Supplements?
I left calcium supplementation for last because many people overly rely on supplements. Supplements are just that; they are meant to “supplement” your diet. Before considering what supplements to take on a ketogenic diet, your priority should be to try and consume adequate nutrition through food before worrying about taking any supplements.
There are certain cases when we can't obtain adequate nutrition from our diet alone. In the event you cannot consume the recommended doses in your diet; supplements can be a great tool to make sure you receive sufficient levels of vitamins and minerals.
The two primary forms of calcium supplements are carbonate and citrate.
Calcium carbonate is the cheapest form of calcium and provides 40 percent elemental calcium. Elemental calcium is crucial because it's the actual amount of calcium in a supplement.
For example, if a supplement claims to have 1,000 mg of calcium carbonate, that equates to 400 mg o elemental calcium. 10
Furthermore, calcium carbonate is better absorbed when taken in smaller doses and best absorbed with food.
Calcium citrate is absorbed well with or without food. Twenty-one percent of calcium citrate comes in the form of elemental calcium.
When it comes to choosing which form of calcium to supplement with, consider these things:
Those who suffer from low stomach acid, taking acid blockers, or have IBS may benefit more from taking calcium citrate over calcium carbonate.
When it comes to getting adequate amounts of calcium on keto, many factors may impact absorption, including age, vitamin D intake, and other components in food such as physic and oxalic acid.
Keto-Friendly foods rich in calcium include seeds and nuts, especially almonds, dark leafy vegetables, cheese, and canned fish with the bones.
What are your favorite sources of calcium on keto? Do you supplement calcium?