What Causes Falsely Low HbA1c Result in Hemolysis and Blood Loss?

In the presence of glucose in the blood, hemoglobin may undergo a glycation process and turned into glycated hemoglobin. HbA1c is one form of glycated hemoglobin. Measured HbA1c represents how much glucose in the blood for the last 120 days (the age of erythrocytes).

In hemolysis and blood loss, measurement of HbA1c will yield falsely low result, giving us a false idea that blood glucose in the last 120 days has been low while it actually has not. Is this phenomenon caused by a reduction in the amount of hemoglobin?

Does Vitamin D Promote Type 1 Hypersensitivity?

Vitamin D is known to suppress adaptive immune response by several mechanisms. One of which is carried out through shifting T cell differentiation in favor of T helper (Th) 2 instead of Th1. Unlike Th1, which specializes in inflammation and killing of bacteria & protozoa, Th2 specializes in anti-inflammation, killing of helminthes, and type 1 hypersensitivity. Thus, does its use promote allergic reaction?