Retesting vitamin D three weeks into supplements
Vitamin D moves slowly; levels take roughly three months on a steady dose to reach their new plateau. Testing early shows a half-finished number, prompts an unnecessary dose change, and wastes AED 180–350. Set a calendar reminder for twelve weeks and resist the urge.
Hopping between labs and comparing the numbers
Different laboratories use different assay methods and reference ranges, so a small shift between two labs may be methodology, not biology. For anything you track over time — HbA1c, lipids, thyroid, ferritin — keep the same vendor and lab, and let the trend do the talking.
Booking a fasting draw for 4pm
A 4pm fasting appointment means either skipping lunch after a token breakfast — which is not a proper 12-hour fast — or fasting all day and producing a dehydrated, miserable sample. Outside Ramadan, fasting draws belong in the morning. If mornings are impossible, split the panel and do the non-fasting tests in the evening.