Calcium is well known for ‘healthy teeth and bones’, but what people aren’t always aware of is how essential calcium is for your muscles.
Sliding filament Theory
In order to contract our muscles, we go through a process called the sliding filament theory. This process surrounds 2 proteins called Actin and Myosin.
Actin is almost like a thin rope and Myosin is more like a thick ‘golf club’, if you like.
When your brain receives a signal to contract a muscle, it also releases calcium ions from a storage place in the muscles called the Sarcoplasmic Reticulum. Now stay with me here.
These calcium ions then bind to a protein called troponin, (which is found on the actin filaments).
When calcium binds to troponin, it causes the troponin to change shape, exposing binding sites on the actin.
These sites are where the myosin heads (still imagining the golf club shape) can grab on to the actin and start pulling it toward the center of the muscle.
As the process continues, the actin and myosin slide past each other, leading to muscle contraction.
Without calcium, this process cannot occur.
Functions and Requirements:
- Aids blood clotting
- Regulates heart rhythms
- Normal functioning of many enzymes
Calcium is what is known as a ‘major mineral’ as opposed to a ‘trace mineral’- this means it is required in doses of more than 100mg a day. In the case of calcium, the RDA (recommend daily allowance) is 1000mg.
Do you need to supplement calcium?
Generally, no.
Whilst there is some chitter chatter around increased need for athletes to have more calcium (which does make sense)- the consensus is the same RDA as gen pop.
Perhaps if you are vegan, or suffering from osteoporosis you may benefit from supplementing however it is wise you refer with your GP. Calcium carbonate and calcium citrate are the two most recommended forms of supplementation.
You do however have to ensure you are eating enough as you can only get calcium from consuming it.
Some sources include:
- dairy, inc milk, cheese, and yogurt
- canned fish with bones, such as salmon or sardines
- leafy greens including collard greens, spinach, and kale
- edamame and tofu
- beans and lentils
- fortified foods and drinks (this means foods that have been enriched with something -calcium in this case).
- seeds- chia/poppy/sesame