Bio D3 Plus is the brand name of a combination product that contains calcitriol and vitamin D-3. It is used in several conditions such as rarified bones (osteoporosis), low blood calcium levels of patients with kidney problems and hypothyroidism (inadequate functioning of thyroid glands). In India, due to aggressive promotion, many such medicines are being over prescribed and overused; hence one needs to be careful while assessing the rationality of the prescription. Side effects include: Hypercalcaemia (that can lead to kidney stones), hypercalciuria (calcium in urine), drowsiness, weakness, nausea, diarrhoea, constipation, skin irritation, kidney toxicity, calcification of muscles and other non-bone tissues, dehydration, abdominal pain etc.