From Exhausted to Energized: How Blood Tests Revealed My Iron Deficiency

Her yearly checkup, done six months earlier, looked fine. Her complete blood count, a test that checks red and white blood cells, came back normal. Her hemoglobin, the protein in blood that carries oxygen, was 12.6 g/dL. That is inside the normal range. Her blood sugar and cholesterol were normal too. The report said she was healthy.

Quick answer

Low iron can drain your energy long before you count as anemic. A standard blood count can look normal while your ferritin, the marker for stored iron, sits nearly empty. Ferritin under 50 ng/mL with fatigue, hair loss, or brain fog points to a real iron shortage. Iron taken with vitamin C, plus a check for what is causing the loss, usually turns things around within 12 weeks.

What a deeper blood panel showed

A more complete panel told a different story. Here is what it found:

• Hemoglobin: 12.4 g/dL. Still inside the normal range.
• MCV: 81 fL. This measures red blood cell size. It sat at the low end of normal.
• RDW: 15.2%. This measures how much red blood cells vary in size. It was mildly high.
• Ferritin: 14 ng/mL. This measures stored iron. It was very low.
• Iron: 48 µg/dL. Low.
• Transferrin saturation: 13%. This measures how much iron your blood is carrying. It was low.
• TSH: 2.4 mIU/L. A thyroid marker. Inside the normal range.
• Free T3: 2.5 pg/mL. An active thyroid hormone. At the low end of normal.
• Vitamin D: 22 ng/mL. Low.
• B12: 380 pg/mL. Borderline low.

Anna's hemoglobin looked normal on the standard test. But her ferritin, the marker for stored iron, was almost empty. Think of ferritin like a fuel tank and hemoglobin like the fuel gauge. Anna's gauge still read "fine," but her tank was nearly dry. She was low on iron at a deep level, even though she was not yet counted as anemic.

What the doctor's notes said

In plain terms, the doctor's summary said Anna had a true iron shortage. Her low ferritin and low transferrin saturation both pointed to it. Her low normal MCV and high RDW were early warning signs too. Her symptoms fit the pattern well: tiredness, thinning hair, weak workouts, and brain fog.

The plan was simple. Take an iron supplement every other day with vitamin C, and stay away from coffee, tea, and calcium around dosing time. Add a vitamin D supplement. Retest in 12 weeks. The doctor also suggested Anna see a gynecologist to check whether her periods were a source of the iron loss.

A standard checkup that only flags a "normal" complete blood count would have missed all of this. Another story shows the same gap, where a full panel found what three normal checkups missed.

The 12 week plan

Anna made three changes.

1. Iron supplement. 65 mg of elemental iron every other day. She took it with a glass of orange juice for vitamin C, and never close to coffee or dairy.
2. Vitamin D supplement. 4,000 IU a day.
3. Small diet shifts. More eggs, occasional red meat, and pairing plant iron sources like lentils and leafy greens with vitamin C.

She also saw her gynecologist, who noted that her periods were on the heavier side. They discussed options for later, but just having the context helped Anna understand her body better.

What changed at 12 weeks

Her retest showed real progress:

• Hemoglobin: 13.4 g/dL. Up from 12.4.
• MCV: 86 fL. Up from 81.
• RDW: 13.8%. Down from 15.2.
• Ferritin: 58 ng/mL. Up from 14.
• Iron: 95 µg/dL. Up from 48.
• Transferrin saturation: 28%. Up from 13.
• Vitamin D: 44 ng/mL. Up from 22.
• B12: 580 pg/mL. Up from 380, a modest gain from food.

The bigger story was how Anna felt. Her energy came roaring back. Workouts felt normal again. Her mind felt clear. Her hair stopped shedding as much, though hair takes longer to fully bounce back.

What this story teaches us

Anna's pattern shows up again and again in adult Filipino women:

• Hemoglobin looks "normal," but ferritin is nearly empty
• A standard blood count misses this kind of iron shortage
• Fatigue, thinning hair, weak workouts, and brain fog get blamed on stress
• Heavy or long periods are often the hidden cause
• Plant based eating can make the problem worse if iron is not managed
• Iron supplements plus small diet changes usually fix it within 12 weeks

If you have periods and you feel drained with a "normal" blood count, ferritin is the test worth asking for.

When should you test ferritin?

If you have periods:

• Test ferritin once a year
• Test every 6 months if it has been low before, or your periods are heavy
• Test anytime you notice new fatigue, hair loss, or weaker workouts

For everyone else:

• Include it in your first full panel
• Repeat based on your doctor's advice

Curious what your own ferritin looks like? See how a &you Labs panel checks your iron levels alongside the rest of your blood work.

Frequently asked questions

Is "Anna" a real patient?

No. Anna is a made up example built from patterns we see often. The numbers and results reflect what we regularly find, but the story itself is for illustration.

How fast does iron treatment work?

Energy often improves in 4 to 8 weeks. Hair takes 3 to 6 months to visibly recover. Ferritin itself often needs 12 or more weeks to rebuild. Always retest to confirm progress.

Why take iron every other day instead of daily?

Newer research shows that taking iron every other day helps your body absorb it just as well, with fewer stomach side effects. Daily dosing works too, but some people find it harder on the stomach.

Should I worry about taking too much iron?

For women with periods and low ferritin, the risk is small. For men, women past menopause, or anyone with a genetic condition called hemochromatosis, taking iron without guidance can cause a harmful buildup. Always test before you start supplementing.

What if my ferritin does not improve with supplements?

A few things could be going on: ongoing blood loss from heavy periods or the gut, poor absorption from a condition like celiac disease, inflammation that hides the true number, or a dose that is too low. A doctor can help sort out the cause.

Key takeaways

• A "normal" hemoglobin does not rule out low iron. Ferritin is the more sensitive test.
• Low ferritin, under 50 ng/mL with symptoms, can cause fatigue, hair loss, weak workouts, and brain fog even when hemoglobin looks fine.
• This pattern is very common in Filipino women who have periods.
• Iron supplements plus small diet changes usually fix it within 12 weeks.
• Yearly ferritin testing makes sense for anyone with periods, no matter what the blood count shows.

Curious what your blood is really telling you? Book your &you Labs panel. Your results come back with both the standard range and the healthy target range, plus a doctor's written interpretation.