Calcium

Calcium will be on our next exam and I read through it today and got so excited because it's so interesting, so now I have to blog about it. (Yes, I know I'm a nerd) So here you have an introduction to this mineral.

Most of your calcium in the body is in your bone structure -->1,2-1,3 kg or about 2,5 pounds. You also have a some in your blood (about 1 % of your body weight).

The ratio between calcium and phosphorus is 2:1 in the bones. This means that if you don't have enough calcium or phosphorus, it will effect the levels of the other mineral.

You absorb 15-80 % and is regulated by several different hormones (calcitonin, PTH) from thyroid and the parathyroids (sköldkörtel och bisköldkörtlar) And an ongoing exchange of calcium happens (blood, bones, reabsorption from kidney's etc) directed by these hormones. Two other important factors affecting the level of calcium is vitamin D status and availability, and the kidney's regulation of secretion. 
This means that is is very important to have enough vitamin D - otherwise you won't absorb enough calcium.
The body is very good at regulating all these things though.


Some things inhibits the absorption and they are phytate and oxalate. Phytate are found in whole grains and especially the outer parts of the cereal. Phytate actually inhibits many different vitamins and minerals so it can definitely be something important to remember. If you want to remove the phytate, you can bake sourdough bread, or simply combine your food in that way that you do not eat phytate with food rich in vitamins and minerals. Oxalate can be found in, for example, rhubarb, spinach and soy.
 Large amounts of protein and sodium also makes the kidneys excrete more calcium through the urine - which means greater losses.


Large intake of calcium has shown to be positive for the blood pressure and lowers the risk of cardiovascular diseases.

And then when it comes to bones and bone fractures... Both vitamin D and calcium are important to prevent fractures but don't forget that things like not smoking and exercising are even more important. When you are 20-25 years old, then your bones have reached it's best state, that's why it's important to exercise when you are young so you will get good bones as you can not improve this after this age. However, if you continue to exercise after that, the degradation (nedbrytning) will go slower.
Older women has a much higher risk of getting bone fractures, and one reason could be that they have less estrogen and estrogen inhibits the degradation. It's also important for us swedish people to think about our vitamin D intake (because of the lack of sun where we get most of our vitamin D) as this higher the risk of fractures.


The swedish recommendations on calcium intake is 800 mg per day for adults. You find a lot of calcium in milk, cheese, legumes (baljväxter), green leafy vegetables and nuts. Dried figs and shrimps also contains quite a lot of calcium. If you don't eat milk or products of milk as cheese, then you might need to think an extra thought of what you are eating so your intake will be enough. I have pretty much stopped eating products from cow such as milk, cream and cheese and I have not thought at all about the calcium intake so I know I need to start doing that.
The reason why I (pretty much) stopped eating that is because of that all the hormones they are giving the cow will end up in the fat - which means in the milk/cream/cheese products. It also highers the risk for inflammation in the body. You need 20 kg of milk to produce 1 kg of cheese... that is a lot of hormones concentrated in cheese... That didn't really have much to do with calcium but wanted to through it in there.. I have learned that from Stig Bengmark, the doctor I have mentioned several times before. I will go on another lecture with him hopefully next week and I will ask him more about that then as I think that is an extremly interesting subject!


Other sources are Näringslära för högskolan from 2008.