Six months of eating roughly 1,100 calories a day and my ferritin has halved, which I did not connect to the intake until somebody pointed it out.
The question I want answered is which deficiencies actually show up when intake drops this far, and which are worth testing rather than supplementing blind.
Not looking for reassurance. Looking for the part I have got wrong.
laura_annarbor said:Six months of eating roughly 1,100 calories a day and my ferritin has halved, which I did not connect to the intake until somebody pointed it out.
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 64 to 31. Supplementing.
- Vitamin D: Was already low (23 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!
Dr.KarenChen said:Vitamin and mineral labs to check while on micronutrients — my doctor orders these quarterly: B12: Can drop due to reduced GI absorption.
Iron studies on micronutrients — important especially for women:
| Marker | Baseline | Month 6 | After Supplementation |
|---|---|---|---|
| Ferritin | 78 | 26 | 58 |
| Iron | 108 | 63 | 96 |
| TIBC | 338 | 408 | 348 |
| Transferrin Sat | 30% | 18% | 29% |
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.
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Shop Reference Standardslaura_annarbor said:Six months of eating roughly 1,100 calories a day and my ferritin has halved, which I did not connect to the intake until somebody pointed it out.
This is my experience too, for whatever a second data point is worth.
Adding the clinical framing, because it changes how the question reads.
Vitamin D levels and micronutrients: an often-overlooked connection. Obese individuals store vitamin D in adipose tissue, making it less bioavailable. As you lose fat, vitamin D can actually increase WITHOUT supplementation.
My trajectory: Baseline 18 ng/mL → Month 6 (with supplement) 42 ng/mL → Month 12 48 ng/mL. Target is 40-60 ng/mL. Adequate vitamin D supports immune function, bone health, and mood — all relevant during weight loss.