What is one primary function of insulin?

Insulin plays a vital role in glucose metabolism, primarily by promoting the uptake of glucose by cells. After we consume food, especially carbohydrates, blood sugar levels rise. In response, the pancreas secretes insulin, which facilitates the absorption of glucose from the bloodstream into the cells. This process is essential for providing energy to cells, particularly in muscles and fat tissues, and helps to regulate blood sugar levels by lowering them after a meal.

By encouraging this uptake, insulin ensures that glucose is utilized effectively and prevents hyperglycemia, which can lead to various health issues over time if not managed properly. The other potential functions mentioned in the choices do not align with the primary actions of insulin; rather, they pertain to different hormones or functions within the body's metabolic processes. For example, increasing blood sugar is the opposite effect of what insulin does, while glucagon is a hormone that typically works in opposition to insulin by raising blood sugar levels. Additionally, insulin is not directly involved in regulating calcium levels in the body.