 [ Symptoms ] will my baby is feeding schedule change when on a baby bottle [ Disease ] although studies show low vitamin d is linked to poor diabetes control it would not necessarily give you a false reading a hemoglobin a1c higher than 6 5 indicates diabetes the fact that your fasting blood glucose was normal is probably why your doctor is having you re take your hemoglobin a1c hopefully the second test will give you some clarity the a1c is the average of your readings for 6 months a 9 1 reading puts your average reading at around 170 average not exact that is diabetic mornings without eating should average 80   130 two hours after eating should be under 180 if the 170 is a fasting reading you have diabetes my opinion and what i was told in classes not all methods for measuring hba1c are totally specific  one of the usual substances incriminated is hb f or foetal haemoglobin which only should usually be present in small amounts in adult blood however some people do carry larger amounts which can interfere with the assay