HOLI Guide to Nutrition: Calcium
LET'S LEARN ABOUT NuTRITION
Hello, and welcome (back) to our HOLI BLOG, beautiful soul on the Internet!
Thanks for joining us today for another post in our HOLI SH*T: Nutrition series. In a previous post, we have talked about Carotenoids and their impact on our health. Today, we are keeping with the C-theme, and taking a closer look at Calcium. One of the more known nutrients around. However, there are a few misconceptions or myths surrounding calcium that we would like to comment on.
As a quick reminder: This post is not intended as medical advice in any way. While we are sharing our thoughts and research on topics like how to utilize specific nutrients and their effects in order to aid in healing our bodies, it is merely an attempt at putting together useful and educational information from different sources. We do not have knowledge of your personal health and are not equipped to offer anything but generalized information that is merely intended to be an introduction to a topic and an invitation to conduct your own research. We know, however, that the first step is always the hardest. Hence, our attempt to provide you with a base understanding, so you can go from there.
Let us all try to demystify the concept of what "a healthy diet" looks like. Let us talk about Calcium.
What Is calcium and where does it come from?
Calcium is among the more important minerals in the body. 99 percent of the calcium is found in bones and teeth, amounting to a mass of slightly over 1 kg. Out of the 1 percent that is roaming freely in the body's bloodstream, about 45 percent is ionized calcium and 55 percent is bound to a protein.
Adults are recommended to absorb about 1000 mg of calcium via food consumption each day. Lots of plants, plant-based products, and even items like bottled water, juices, or plant-based milk are sources of calcium. The body cannot produce calcium on its own, therefore we rely on regular and adequate calcium intake via food consumption.
Generally, teenagers, elderly people, and people in their menopause require a higher calcium intake. Specifically, people in their menopause should focus on regular calcium intake as their hormonal balance is disturbed and hormones like estrogen are responsible for the intake of calcium into the bone structure.
Let us take a quick look at plants and plant-based foods that are rich in calcium:
Calcium And Health
Calcium plays a central role in a number of different processes in the body. Most commonly, we think of calcium in terms of bone and tooth health. But its impact goes way beyond that. For instance, calcium is essential in blood clotting, muscle contraction, and nerve activity, as well as the functioning of the heart, lungs, and kidneys.
These functions are so vital that the body is meticulous about keeping a steady amount of calcium in blood and tissue. When calcium levels drop below a certain point, the parathyroid hormone signals to the bones to release calcium into the bloodstream. It also initiates processes to improve the absorption of calcium in the gut and slow down the release of calcium via urine. On the other hand, when there is an excess amount of calcium in the body, the hormone calcitonin signals the bones to stop releasing calcium into the bloodstream and signals the kidneys to rid more of calcium via urine.
This may sound a little radical but bone is actually living tissue. Bones are constantly broken down and build up again. When we intake plenty of calcium, are physically active, and spend a decent amount of time in the sun, bone production exceeds bone destruction up to the age of 30. After that, destruction tends to exceed bone production. This is where bone loss can happen. However, calcium cannot completely prevent bone loss from happening as it is a natural part of life.
Note, that calcium consumption should be regular and adequate. Increasing your calcium intake past a certain age will not help as absorption becomes more difficult and the effects are different from earlier stages in life.
Over 1/2 of the population has become or is at risk of becoming deficient in calcium. There is an array of different reasons for the deficiency, ranging from nutrition, excessive consumption of coffee and alcohol, taking certain medications, or athletes who sweat excessively. Certain health problems can cause deficiency as well, like hormonal imbalances, diseases of the kidneys or thyroid, and even other deficiencies like magnesium or vitamin D.
Vitamin D deficiency has become one of the most common reasons for calcium deficiency. Technically, vitamin D is not a vitamin but a pre-stage of a hormone. The body has the ability to produce its own vitamin D. However, to do so the body has to be exposed to sunlight.
Most of our calcium is absorbed in the gut. Vitamin D is responsible for picking up the calcium and building it into the bones and teeth. Exposing yourself to sunlight for 5-25 minutes a day can be enough to fuel and fill your body's vitamin D tank.
Milk (Products) as the main source of calcium?
You know our stance on animal products, so we are certainly biased when it comes to their consumption. Ethical consumption is, in our opinion, not possible, for a number of different reasons that all lead back to animal and environmental rights.
When researching we have found countless sources, both in favor and against the consumption of milk. What got us thinking, though, were the articles that specifically advised against consuming plant-based products to meet the requirements for calcium. The arguments were interesting – to say the least.
In the past, we have talked about so-called anti-nutrients when discussing the nutritional value of certain fruits and vegetables. Anti-nutrients lower the body's ability to absorb certain nutrients. One of the foods that we have mentioned as being high in calcium is spinach.
However, spinach is also high in an anti-nutrient called oxalic acid, which is also known as oxalate.
Oxalate, like other anti-nutrients, can bind to minerals, like calcium, to form compounds. This significantly reduces the body's ability to absorb the calcium in spinach. These compounds are later passed via stool or urine.
Now, this is not exactly ideal. We have a food that is high in calcium but if only around 5 percent of the calcium from spinach can be absorbed then its purpose may not lie in providing us with calcium.
This does not leave us with animal products as our only calcium source, though. We have to take different aspects into account:
How much we eat of one food item
What we eat that food item with
and something called bioavailability, which we will get into in a second.
The average person – even those who follow an omnivorous diet – will typically eat larger quantities of fruits, and especially vegetables compared to animal products. We may need larger portions of plant-based items to meet the requirement for calcium but this is not necessarily a bad thing. Many plants are low-caloric but otherwise high in nutritional value. We can easily eat an entire bowl of leafy greens and feel full and satiated while drinking the recommended 3 glasses of milk can cause digestive issues, breakouts on the face and body, and is not exactly what one would consider a healthy and balanced meal.
Not only do we eat larger portions of plant-based meals, we usually do not stick to one item exclusively. Think of some of the calcium-rich foods we have mentioned: Several of these items can be used to create a meal that is not only high in calcium but an array of wonderful nutrients that our bodies are craving. This goes far beyond munching on a handful of spinach. We can think of at least a dozen of different combinations off the bat.
Again, we are certainly biased and not afraid to show it. However, there is one more aspect that we find is worth mentioning. Bioavailability makes a compelling case as to why plants should not be overlooked as a source (or the source) of calcium.
When we talk about bioavailability we are talking about the amount of calcium that the body can absorb and utilize for its processes. When we look at nutritional labels we can find the amount of calcium (or any other nutrient for that matter) that is present in the item. This is, however, not the amount of calcium the body will absorb.
Some foods have a higher bioavailability than others. According to Harvard's SPH Nutrition Source, the bioavailability of dairy foods is at about 30 % absorption. The bioavailability of bok choy, on the other hand, is at 50 %. While a cup of milk has 300 mg of calcium, only about 100 mg will be absorbed and used by the body. A cup of bok choy contains 160 mg of calcium and 80 mg can be absorbed by the body.
Thus, making milk and bok choy almost equal in bioavailable calcium.
So when we say that spinach is high in calcium it is technically correct but the oxalate content lowers spinach's bioavailability to only about 5 percent, leaving a mere 13 mg of calcium per cup from the initial 260 mg.
This does not mean that spinach should be avoided altogether. Anti-nutrients can actually be extremely helpful as many of them contain antioxidant properties. They can have positive health benefits on the body like lower cholesterol.
Your safest bet would be to diversify your portfolio. No, that is not financial advice – although it probably could be. Eating a variety of different calcium-rich foods with every meal will guarantee that your calcium requirement is met and it will prove a lot more colorful and flavorful than if you were to rely on three glasses of cow's milk to meet your goal.
At the end of the day, what we are trying to say is that you do not need to consume dairy products to be healthy and meet your calcium requirement.
Calcium plays a big role in our bone and teeth health. But it is also a key player in blood clotting, muscle contraction, and regulating heart rhythms and nerve functions. In today's society, almost 1/2 of people have become or are at risk of becoming deficient in calcium.
Teenagers, elderly people, and people in menopause require higher calcium intake compared to all other age groups. Dairy is far from the only source of calcium. Many plants and plant-based products, and even bottled water contain calcium. The nutritional labels do not necessarily depict the amount of calcium that the body is able to absorb and use. The bioavailability changes from item to item, with plant-based milk, juices, or tofu having a similar bioavailability as dairy milk, almonds ranging a little lower, spinach a lot lower, and bok choy higher.
Thank you for stopping by today. We hope that you enjoyed the second post in this series, and we would be excited to have you back here with us next week. Until then, stay kind.
xx HOLI BLOG TEAM