🍪 The GLP Lounge uses cookies to improve your experience, analyze traffic, and personalize content. By continuing to use this site, you agree to our Cookie Policy.
Evidence-based GLP-1 & peptide discussion since 2023
ForumsLab Results & BiomarkersFerritin and iron studies on GLP-1 — reduced intake considerations

Ferritin and iron studies on GLP-1 — reduced intake considerations

BethLabQueen Mon, Jun 1, 2026 at 2:50 AM 3 replies 237 viewsPage 1 of 1
BethLabQueen
Senior Member
1,234
5,678
May 2024
Virginia
Online
Jun 1, 2026 at 2:50 AM#1

Writing this once so I can stop repeating it across threads. It is about micronutrient cover, and it is deliberately narrow — everything I am not confident about is marked as such.

What is actually established

A sustained drop to 1,100 or 1,200 calories reliably under-delivers a predictable set: B12, vitamin D, iron, folate, zinc and magnesium. Two of those are worth testing rather than guessing because the tests are cheap and the symptoms overlap with everything else — ferritin and B12. The rest a decent multivitamin covers, and there is no benefit in megadosing any of them.

The condition it depends on

The caveat that iron should be tested before supplementing, not after. Supplementing iron into normal stores is unpleasant at best and harmful in haemochromatosis.

The practical version

Cheap and worth having: ferritin, B12, vitamin D. Everything else on the deficiency list is adequately covered by a standard multivitamin at ordinary doses.

What I am not sure about

What would genuinely help is knowing which deficiencies actually show up when intake drops this far, and which are worth testing rather than supplementing blind. I would rather have one careful answer than five confident ones.

— BethLabQueen · corrections welcome and will be edited into this post with credit
24 2maya_sedona, stefan_berlin, Dr.EM_Chicago and 21 others
Reply Quote Save Share Report
Dr.PeteFamMed
Senior Member
2,012
9,234
Jan 2024
Minneapolis, MN
Jun 1, 2026 at 3:00 AM#2
BethLabQueen said:
A sustained drop to 1,100 or 1,200 calories reliably under-delivers a predictable set: B12, vitamin D, iron, folate, zinc and magnesium.

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.

25 3tommy_boulder, hyun_seoul, jim_asheville and 22 others
Reply Quote Save Share Report
anders_CPH
Senior Member
1,567
7,234
Feb 2024
Copenhagen, DK
Jun 1, 2026 at 3:10 AM#3
BethLabQueen said:
A sustained drop to 1,100 or 1,200 calories reliably under-delivers a predictable set: B12, vitamin D, iron, folate, zinc and magnesium.

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 55 to 22. Supplementing.
  • Vitamin D: Was already low (22 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!

26 4AussieAnna, BethLabQueen, ChrisMacros and 23 others
Reply Quote Save Share Report

PeptideMeter — Independent Peptide Analytics

Community-driven peptide testing and vendor rating platform. Transparent results. Unbiased analysis. Trusted by thousands.

View Results
chris_chi24
Member
389
1,678
Sep 2024
Chicago, IL
Jun 1, 2026 at 3:20 AM#4
anders_CPH 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:

MarkerBaselineMonth 6After Supplementation
Ferritin711946
Iron1015189
TIBC311381341
Transferrin Sat31%16%26%

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.

27 5PurityPaulOR, MaxMetOK, MounjBrad and 24 others
Reply Quote Save Share Report
stefan_berlin
Member
234
1,123
Oct 2024
Berlin, DE
Jun 1, 2026 at 4:12 AM#5
Dr.PeteFamMed said:
Vitamin D levels and micronutrients: an often-overlooked connection.

This matches mine closely enough to be worth saying so out loud.

28 6TrialTracker_MD, JennaRN, LabKate and 25 others
Reply Quote Save Share Report

Similar Threads

Optimal lab testing frequency on GLP-1 — evidence-based schedule5 replies
A1C from 7.2 to 5.1 — my bloodwork transformation19 replies
Thyroid function monitoring on GLP-1 — TSH and free T4 trends3 replies
Lipid panel improvements mega-thread — share your numbers19 replies
Liver enzymes trending down on GLP-1 — ALT/AST normalization17 replies
ForumsNewTrendingMembersAccount

Log In

Forgot password?
No account? Register