HbA1c is a blood test that measures the share of haemoglobin carrying glucose, averaging glycaemia over the previous 8 to 12 weeks. Practitioners use it to see the longer-term picture behind a single fasting glucose and to track change across a three-month plan. It is only reliable when red cell lifespan is normal, so iron deficiency, blood loss or haemoglobin variants can distort it.
| Test type | Measured in a blood sample |
|---|---|
| Measurements required | HbA1c only |
| Sample and collection | Blood draw at a collection centre |
| Preparation | This test doesn't need fasting on its own. |
| Turnaround | 3 to 5 business days |
| Available through | Diabetes & Glycaemic Studies, part of the Baseline Health Check. Also in: Full Body Health Check, Metabolic Panel, Weight Management Test, HbA1c Test. |
| Pricing | Included in the $99 Baseline Health Check |
| Results | Returned in the Vively practitioner platform, beside your client's other markers |
What are the HbA1c reference and optimal ranges?
| Typical lab reference | Vively optimal | |
|---|---|---|
| Adults | 20 to 39 mmol/mol (4.0 to 5.7%) | 4.0 to 5.3% (up to about 34 mmol/mol) |
| Adults, Australian diagnostic thresholds | 42 to 47 mmol/mol (6.0 to 6.4%) higher risk; 48 mmol/mol (6.5%) or above diabetes range (doctor to confirm) | Not applicable |
Labs set their own range, so read the result against the range on the client's report (RCPA). The optimal range is a monitoring target, not a diagnostic cut-off. The 42 and 48 mmol/mol figures are risk and diagnostic thresholds a doctor applies, and HbA1c is only reliable when red cell lifespan is normal.
Check a client's HbA1c result
Enter the value from your client's lab report to see where it sits against the typical lab range and the Vively optimal range.
A guide only, not a diagnosis. One result is a starting point: read it with symptoms, history and a repeat test. Labs differ, so check the result against the range on your client's report. Nothing you enter is stored or sent.
How do you arrange HbA1c testing through Vively?
- Get verified. Practitioners with a recognised qualification or membership (ATMS, NHAA, ANTA, Dietitians Australia, NSA, CMA or Ahpra registration) can request free practitioner access.
- Choose a panel. Log in to the practitioner platform and pick a panel that includes HbA1c, or build your own. It is included in the $99 Baseline Health Check.
- Client collects. Your client collects at a partner collection centre, with their request on their phone or printed.
- Review results. Results come back to you in the practitioner platform, beside your client's other markers, ready for the follow-up consult.
Which Vively panels include HbA1c?
Log in to the practitioner platform to view a panel in full, or build and save your own from 100+ tests and panels.
- Baseline Health Check74 markers across 11 lab groups$99
One fasting blood draw.
Full Blood CountUrea, Electrolytes & CreatinineLiver Function TestsCalcium, Phosphate & MagnesiumLipid StudiesDiabetes & Glycaemic StudiesIron StudiesThyroid Function Tests+3 moreLog in to view this panel - Log in to view this panelMetabolic Panel3 markers · Heart & metabolicPrice on sign-up
- Weight Management Test27 markers · Heart & metabolicPrice on sign-upHbA1cTotal CholesterolLDL CholesterolHDL CholesterolNon-HDL CholesterolTriglyceridesFree testosteroneSHBG+19 moreLog in to view this panel
Why does the optimal range sit there?
No separate optimal range: HbA1c reflects glycation across the life of the red cell, so anything that changes red cell survival moves it with no change in glucose.
A single target would mislead in clients with iron deficiency, haemoglobin variants or kidney disease.
Australia accepts HbA1c for diagnosis at 48 mmol/mol (6.5%) or above. The Australian position paper by d'Emden and colleagues (Medical Journal of Australia, 2012) treats 6.0 to 6.4% (42 to 47 mmol/mol) as higher risk.
Within the reference range, read HbA1c with these markers and against the client's own results from the same lab.
What should HbA1c be read with?
- ContextHbA1c raised, fasting glucose normal
Possible glucose rising after meals; check ferritin and MCV, as iron, B12 or folate deficiency can also inflate HbA1c.
- ContextHbA1c 42 to 47 mmol/mol with high fasting insulin
Often seen with established insulin resistance and higher diabetes risk; worth GP review and a structured plan.
- LowLow HbA1c with low haemoglobin
Possible shortened red cell survival from haemolysis or blood loss, which makes HbA1c read low.
- ContextHbA1c 48 mmol/mol or above
In the diabetes range; needs GP confirmation.
What can affect a HbA1c result?
- Iron, B12 or folate deficiency, which can raise HbA1c independent of glucose.
- Recent blood loss, transfusion, haemolysis or iron treatment, which can lower it.
- Haemoglobin variants such as thalassaemia trait, which can affect some assays.
- Pregnancy, which lowers HbA1c through faster red cell turnover.
- Chronic kidney disease and erythropoietin treatment, which can lower it.
- Timing: about half the result reflects the last 30 days, so a recent change in diet shows only partly.
When should you refer the client to their GP?
- 48 mmol/mol (6.5%) or above: GP review to confirm diabetes.
- 42 to 47 mmol/mol: GP review to assess diabetes risk and agree retest timing.
- Thirst, frequent urination, blurred vision, recurrent infections or unexplained weight loss.
- Low HbA1c with signs of anaemia, or in a client taking glucose-lowering medicines.
How should a client prepare for a HbA1c test?
Copy or print this to send to your client.
Preparing for your HbA1c test
- This test doesn't need fasting on its own.
- If your practitioner has requested the Baseline Health Check, fast for 8 to 12 hours before a morning collection (water is fine).
- Tell your practitioner about any recent blood loss, blood transfusion or iron treatment, as these can change your HbA1c.
- Take your pathology request to any of 4,000+ collection centres. Bring it printed or on your phone.
- Keep taking prescribed medicines as usual unless your doctor tells you otherwise.
- Results usually take 3 to 5 business days and come to your practitioner. Book your results appointment for after that.
How do practitioners use HbA1c with clients?
HbA1c moves slowly, so retest no sooner than three months after a plan starts and use fasting insulin or a continuous glucose monitor for faster feedback. When HbA1c and glucose disagree, check iron studies before drawing conclusions.
HbA1c FAQs
Can I add HbA1c to a client's request as a nutritionist, dietitian or naturopath?
Yes. Add it to a client panel on the Vively practitioner platform. It is part of Diabetes & Glycaemic Studies in the $99 Baseline Health Check, and is also in Full Body Health Check, Metabolic Panel and Weight Management Test. No account yet? Request free access.
How do I convert HbA1c from mmol/mol to %?
Divide the mmol/mol value by 10.929, then add 2.15. So 42 mmol/mol is about 6.0%, 48 mmol/mol is 6.5% and 53 mmol/mol is 7.0%. Most Australian reports print both units, and many GPs still talk in %, so noting both in your referral letter avoids confusion.
Should I check iron studies before trusting HbA1c?
Yes, when HbA1c and glucose disagree. Iron deficiency lengthens red cell survival and can push HbA1c up with no change in glucose, and iron repletion can then pull it back down. Review ferritin, haemoglobin and MCV alongside HbA1c, and involve the client's GP in any decision to treat iron deficiency.
How long should I wait before retesting HbA1c?
Retest no sooner than three months after a plan starts. HbA1c reflects the previous 8 to 12 weeks, and about half the result comes from the last 30 days, so a recent diet change shows only partly. For faster feedback in the meantime, use fasting insulin or a continuous glucose monitor.
Why would HbA1c read low when glucose looks normal?
Anything that shortens red cell survival pulls HbA1c down. That includes haemolysis, recent blood loss or transfusion, iron treatment, pregnancy, chronic kidney disease and erythropoietin treatment. A low HbA1c alongside low haemoglobin is the pattern to look for. Review the client's haemoglobin, and involve their GP if anaemia is suspected.
References
- d'Emden MC, Shaw JE, Colman PG, et al. The role of HbA1c in the diagnosis of diabetes mellitus in Australia. Medical Journal of Australia. 2012. Source
- Royal College of Pathologists of Australasia. RCPA Manual: Glycated haemoglobin (HbA1c). Source
- Royal Australian College of General Practitioners. Management of type 2 diabetes: a handbook for general practice. 2020.
- Pathology Tests Explained. HbA1c.
- Selvin E, Steffes MW, Zhu H, et al. Glycated hemoglobin, diabetes, and cardiovascular risk in nondiabetic adults. New England Journal of Medicine. 2010.