amsterdam_pete said:

Iron studies on micronutrients — important especially for women: Marker Baseline Month 6 After Supplementation Ferritin 70 23 45 Iron 100 50 83 TIBC…

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.

The figures, for anyone assembling their own picture. Worth stating the units and the reference range whenever you post a number here. A large fraction of the apparent disagreement in these threads is two people using different units and both being right.

KevinCompounds said:

Vitamin D levels and micronutrients: an often-overlooked connection.

Coming at KevinCompounds’s question from a different direction. The mechanism and the magnitude are separate questions. Agreeing that something happens says nothing about whether it happens enough to act on.

A narrower follow-up, since the general answer is now clear:

How long did you give it before you decided it was working?

Closing the loop on my own question.

Closing the loop. The answer turned out to depend on the detail I had left out of the opening post, which is a lesson about how to ask rather than about the subject.