Thanks for your query.
From the brief information provided, your mother may be suffering from Vitamin D deficiency. This can be confirmed by getting Blood Vitamin D level estimation.
Vitamin D facilitates absorption of calcium from the intestine. Poor absorption results due to vitamin D deficiency.
Further, it may be appreciated that the level of calcium in the blood increases very gradually and NOT overnight!
It would recommend that you give her high doses of Calcitriol
(0.5-0.75 mcg) DAILY (instead of D-Rise), till such time Blood Vitamin D level report is received. If Vitamin D is deficient, continue with suggested doses of calcitriol, with monthly Blood Vit D level monitoring.
Shelcal-OS is GOOD ENOUGH.
Consult your doctor who knows what would be best for you.
Dr. Rakesh Karanwal