tony_orlando said:

I started taking a multivitamin as insurance and then found out that two of the things I was actually short of were the two it barely contains.

Blood count monitoring for micronutrients: my doctor noticed my MCV (mean corpuscular volume) trending up at month 6: 88 → 98 fL. This flagged potential B12 or folate deficiency.

Sure enough, B12 had dropped from 620 to 340 pg/mL. Started B12 injections monthly and MCV normalized within 2 months. GLP-1 agonists can impair B12 absorption — this is a real clinical concern that deserves routine monitoring.

DataDave said:

Blood count monitoring for micronutrients: my doctor noticed my MCV (mean corpuscular volume) trending up at month 6: 88 → 98 fL.

Vitamin and mineral labs to check while on micronutrients — my doctor orders these quarterly:

• B12: Can drop due to reduced GI absorption. Mine went from 650 to 380 — now supplementing.
• Iron/Ferritin: Reduced food intake = reduced iron. Ferritin dropped from 66 to 23. Supplementing.
• Vitamin D: Was already low (21 ng/mL), now taking 5000 IU daily.
• Folate: Stable, no issues.
• Zinc: Slightly low, added a multivitamin with zinc.

Nutritional deficiencies are a real risk when you're eating significantly less. Don't skip your labs!

tony_orlando said:

I started taking a multivitamin as insurance and then found out that two of the things I was actually short of were the two it barely contains.

Adding a me-too, because a thread of one person's experience is not much use.

Adding the clinical framing, because it changes how the question reads.

Iron studies on micronutrients — important especially for women:

My ferritin cratered at month 6 from reduced dietary intake. Iron bisglycinate 36mg with vitamin C brought it back up. Don't wait for anemia symptoms — test proactively.