Indication: This combination medication is used to prevent or treat low blood calcium levels in people who do not get enough calcium from their diets.

Insight:

Citracal + D may be used to treat conditions caused by low calcium levels, such as bone loss (osteoporosis), weak bones (osteomalacia/rickets), decreased activity of the parathyroid gland (hypoparathyroidism), and a certain muscle disease (latent tetany).
Directions: Take this medication by mouth with food. Take 1 or 2 tablets per day, per the provider’s directions.
Do not crush or chew extended-release tablets.
Adverse effects include constipation and upset stomach.
Chewable tablets may contain sugar or aspartame. Caution is advised if you have diabetes, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet.

Sources:

Citracal With Vitamin D Maximum Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing - WebMD
CITRACAL + D Dosage & Rx Info | Uses, Side Effects (empr.com)
CITRACAL + D Dosage & Rx Info | Uses, Side Effects (empr.com)