Then 2,000 / 5,000 = 0.4mL = 40 units
Some of our patients are found to be deficient in Vitamin B12, and through our physician prescribing appropriate vitamin supplementation, some individuals note an improvement in energy level, she says
Ive felt no side effects, but truth be told, Ive felt no difference in my appetite either
For B12 to be absorbed, it requires a protein called intrinsic factor (IF), which is secreted by the stomachs parietal cells (3)

From a laboratory medicine perspective, the Association for Clinical Biochemistry and Laboratory Medicine (ACB) and the Royal College of Pathologists (RCPath) advise that: HbA1c may be unreliable in the presence of haemolytic anaemia, haemoglobinopathies, or nutritional deficiencies affecting red cell biology and the direction of distortion may be high or low Clinicians should document any known haematological conditions when requesting HbA1c, so laboratory staff can flag potential inaccuracies Serum B12 testing should be considered in patients on long-term metformin who are symptomatic or have risk factors for deficiency, in line with MHRA and NICE advice Alternative tests fasting plasma glucose, OGTT, or interim use of fructosamine/glycated albumin should be considered when HbA1c reliability is in doubt The NHS website (nhs.uk) provides patient-facing information on the HbA1c test and factors that can affect its accuracy, which patients may find a useful starting point