Calcium Carbonate is not the best form of calcium to be taking because basically it is chalk and is not absorbed well by the body. It's cheap but you get what you pay for.
Others forms of Calcium are better - wholefood calcium or Calcium Citrate, but usually the Calcium prescribed on the NHS is the cheapest which is Carbonate. Calcium Citrate is also better absorbed by the body because it doesn't need as much stomach acid which - as we get older - is often lower than it used to be.
Even if you are also taking Vit D3, you need to take Magnesium, Boron and Vit K2 to notice improvement/prevent worsening.
These are not available on prescription so it means buying them, and although they are not madly expensive, it is still a financial outlay. However, to me my health is paramount. I have 8 illnesses I am trying to juggle and Osteoporosis and Osteoarthritis are 2 of them.
If I can keep myself pain-free, free of fractures and not bent over and crooked like some of my acquaintances, then the money is worth it. I am not someone who has more than 3 handbags, dozens of pairs of shoes or is for ever buying new clothes and expensive makeup. If you haven't got your health, what's the point?
I saw what Osteoporosis did to a friend of mine who became very bent and in terrible pain, had frequent fractures from the slightest thing (like stretching to get something off a top shelf) and was doped up on drugs and painkillers. This is not what I want for myself.
As I said on another thread, I have studied nutrition for 29 years which I put to good use with my own health.
If anyone wants to PM me, I can give the brand name of the Calcium and Magnesium supplements I use.