HbA1c in non-diabetics does not need to be "reduced." Normal is normal.
To clarify, HbA1c represents the proportion of hemoglobin (Hb) in your blood that is bound to glucose. A certain percentage of glucose binding is normal, with levels of 5.7% or less considered within the non-diabetic range. There’s no evidence or rationale to suggest aiming for a level lower than that.
It's also important to note that HbA1c can vary due to changes in hemoglobin levels, which can be influenced by factors as minor as dehydration. Multivitamins directly do not induce any change as such.
In summary, for non-diabetics, focusing on HbA1c levels is unnecessary. It is not a relevant metric in this context.
Next Steps
Just focus on a good lifestyle and healthy diet. If you're worried about getting
diabetes, consult and know your chances of getting diabetes and how you should approach a healthy lifestyle.