Spinach will work against calcium absorption

My daughter has a child aged two whom she has breastfed for about 18 months. She also has a second child who is now nine months old.

Recently, my daughter had to be hospitalised for very low calcium levels. She has been on tablets since but her calcium levels are fluctuating all the time. She has to have blood tests almost every week. The doctor has said she will be on calcium tablets for life, she is 32 years old.

I have read recently that these tablets can flood the blood and cause hardening of the arteries, and also they are not very effective.