Step 02 · The numbers

Your labs

Enter whatever values you have from your blood work. Leave blank anything you don't have — the tool works with partial information.

From a standard CBC

Red blood cell indices

Hemoglobin (Hb)

g/L

The amount of oxygen-carrying protein in your red blood cells. Too low means anemia. The threshold depends on your life stage.

MCV — mean cell volume

The average size of your red blood cells. Smaller than normal is often the first sign that iron is running low.

MCH — mean cell hemoglobin

The average amount of hemoglobin inside each red blood cell. Lower values usually track with low iron.

RDW — red blood cell distribution width

How uniform your red blood cells are in size. When some cells were made during iron shortage and others weren't, this number rises.

From an iron panel

Iron markers

Ferritin

μg/L

The protein that stores iron in your tissues. A low ferritin is the earliest signal that iron stores are running out.

Transferrin saturation (TSAT)

How much of your iron-transport protein is carrying iron right now. Low means your body isn't getting enough iron to tissues. Very high can signal overload.

Serum iron

μmol/L

How much iron is circulating in your blood right now. Varies a lot by time of day and meals — interpret alongside TSAT.

TIBC — total iron-binding capacity

μmol/L

The total amount of iron your blood could carry if your transport protein were full. Elevated TIBC often signals iron deficiency.

Advanced markers

Less commonly ordered

Soluble transferrin receptor (sTfR)

mg/L

A marker of iron demand at the cellular level. Rises when tissues aren't getting enough iron.

C-reactive protein (CRP)

mg/L

A general marker of inflammation. If elevated, it changes how we read your ferritin — we'll flag this automatically.

Reticulocyte hemoglobin (Ret-He / CHr)

The hemoglobin content of your newest red blood cells. A very early signal of iron shortage — often shifts before ferritin or standard CBC values do.

Symptoms

How are you feeling?

Check anything that applies. Research has documented links between each of these and iron status in women.

Unusual fatigue or low energy Hair shedding beyond normal Brittle nails, spooned nails Restless legs or tingling at night Cravings for ice, dirt, starch (pica) Feeling cold, or cold hands and feet

Absorption-affecting conditions

Any of these apply to you?

Celiac disease Inflammatory bowel disease (IBD) H. pylori infection (current or past) History of gastric bypass or similar surgery Daily use of acid blockers (PPI or H2)

Coffee or tea with meals

How often do you have coffee or tea with meals?

Tannins and polyphenols in coffee and tea can inhibit non-heme iron absorption when consumed with iron-containing foods.

Yes — with meals Yes — but not with meals No or rarely

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Enter at least one value from your labs so we have something to work with.