From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
After 2 units of blood transfusion, calcium supplementation is typically not routinely required unless the patient shows signs of hypocalcemia. If calcium replacement is needed, the most recent and highest quality study 1 suggests that the optimal dosing is still unknown, but a ratio of administered calcium to citrated blood products may be useful in predicting severe hypocalcemia. However, based on the available evidence, 1-2 grams of calcium gluconate (containing approximately 90-180 mg of elemental calcium) administered intravenously over 10-20 minutes is generally sufficient 2, 3, 4. Monitor for symptoms of hypocalcemia such as tingling, muscle cramps, or ECG changes (prolonged QT interval). The need for calcium replacement during blood transfusion stems from the citrate preservative in stored blood products, which binds calcium and can temporarily lower ionized calcium levels. Most patients with normal liver function can metabolize this citrate quickly, making routine calcium supplementation unnecessary. However, patients with liver dysfunction, those receiving massive transfusions (typically more than 4-5 units), or those with pre-existing hypocalcemia may require calcium replacement. If supplementation is needed, follow the initial dose with reassessment of calcium levels and symptoms to determine if additional doses are required. Some studies suggest that severe hypocalcemia is common during massive transfusions and correlates with the number of packed red blood cells transfused 4, and that standardized protocols for recognition and management of severe hypocalcemia during massive transfusions may improve outcomes. It is also important to note that the citrate content of each blood component can be estimated to calculate the ratio of administered calcium to administered citrate, which may be useful in predicting severe hypocalcemia 1. In general, the key is to monitor the patient's calcium levels and symptoms closely and adjust the calcium supplementation accordingly.