## Problem Description and Formulation

The problem is an optimization problem with two variables: 'milligrams of vitamin B12' and 'milligrams of vitamin B7'. The objective is to maximize the function 9.14 * 'milligrams of vitamin B12' + 5.53 * 'milligrams of vitamin B7' subject to several constraints.

## Constraints

1. The cardiovascular support index for 'milligrams of vitamin B12' is 11.
2. The energy stability index of 'milligrams of vitamin B12' is 12.
3. The cardiovascular support index of 'milligrams of vitamin B7' is 10.
4. The energy stability index of 'milligrams of vitamin B7' is 3.
5. The total combined cardiovascular support index from 'milligrams of vitamin B12' and 'milligrams of vitamin B7' must be at least 23.
6. The total combined energy stability index from 'milligrams of vitamin B12' and 'milligrams of vitamin B7' must be at least 16.
7. 4 * 'milligrams of vitamin B12' - 3 * 'milligrams of vitamin B7' >= 0.
8. The total combined cardiovascular support index from 'milligrams of vitamin B12' and 'milligrams of vitamin B7' must be less than or equal to 49.
9. The total combined energy stability index from 'milligrams of vitamin B12' and 'milligrams of vitamin B7' must be less than or equal to 50.

## Gurobi Code

```python
import gurobi

def optimize_vitamins():
    # Create a new Gurobi model
    model = gurobi.Model()

    # Define variables
    vitamin_B12 = model.addVar(name="vitamin_B12", lb=0)  # Assuming non-negative
    vitamin_B7 = model.addVar(name="vitamin_B7", lb=0)  # Assuming non-negative

    # Objective function
    model.setObjective(9.14 * vitamin_B12 + 5.53 * vitamin_B7, gurobi.GRB.MAXIMIZE)

    # Constraints
    r0_B12 = 11
    r1_B12 = 12
    r0_B7 = 10
    r1_B7 = 3

    model.addConstr(r0_B12 + r0_B7 >= 23, name="cardiovascular_support_index_min")
    model.addConstr(r1_B12 + r1_B7 >= 16, name="energy_stability_index_min")
    model.addConstr(4 * vitamin_B12 - 3 * vitamin_B7 >= 0, name="vitamin_B12_B7_relation")
    model.addConstr(r0_B12 + r0_B7 <= 49, name="cardiovascular_support_index_max")
    model.addConstr(r1_B12 + r1_B7 <= 50, name="energy_stability_index_max")

    # Solve the model
    model.optimize()

    # Print the solution
    if model.status == gurobi.GRB.OPTIMAL:
        print("Optimal solution found.")
        print(f"Milligrams of vitamin B12: {vitamin_B12.varValue}")
        print(f"Milligrams of vitamin B7: {vitamin_B7.varValue}")
        print(f"Objective: {model.objVal}")
    else:
        print("No optimal solution found.")

optimize_vitamins()
```