By Dr. Sandra Plybon, MD | Nurture MD Health

You've been taking your iron supplement faithfully. Every single day, like clockwork. And yet, your iron or ferritin levels barely budge. Your fatigue persists. What gives?

The answer might surprise you: taking iron too often is one of the most common reasons supplementation fails. Here's what's actually happening inside your body, and how to work with it instead of against it.

First, a Little About Why Iron Deficiency Is So Common

Before we talk about how to take iron, it's worth understanding why so many women end up needing it in the first place.

Iron deficiency is one of the most widespread nutritional deficiencies worldwide, and women are disproportionately affected. The most common causes include:

• Heavy or prolonged menstrual periods. This is the number one cause in premenopausal women. Even periods that seem "normal" can deplete iron stores over time, especially if cycles are frequent or heavy.
• Perimenopause. Irregular, heavier cycles during the perimenopausal transition can dramatically increase monthly blood loss before periods stop altogether.
• Poor dietary intake. Plant-based and vegetarian diets contain non-heme iron, which is significantly harder for the body to absorb than the heme iron found in red meat and organ meats.
• GI blood loss. Slow, low-grade bleeding from the gut; from conditions like hemorrhoids, polyps, ulcers, or inflammation can quietly drain iron reserves without obvious symptoms.
• Poor absorption. Gut conditions like celiac disease, SIBO, low stomach acid, and H. pylori infection can impair the body's ability to absorb iron regardless of intake.
• Increased demand. Pregnancy, breastfeeding, and intense athletic training all significantly increase the body's iron requirements.
• Chronic inflammation. Inflammation of any kind can elevate hepcidin (more on that below), effectively locking iron out of circulation even when levels appear adequate in food or supplements.

If you're experiencing persistent fatigue, hair thinning, restless legs, brain fog, or shortness of breath with exertion, iron deficiency (even without frank anemia) may be a contributing factor worth investigating.

Meet Hepcidin: Your Body's Iron Gatekeeper

Here's the piece most people — and honestly, many practitioners — don't know about.

Every time you take an iron supplement, your body responds by releasing a hormone called hepcidin. Hepcidin is produced by the liver, and its job is to block iron absorption by degrading a protein (ferroportin) that moves iron from your gut into your bloodstream.

The problem? Hepcidin levels rise within hours of an iron dose and can stay elevated for up to 24 hours. That means if you take iron every morning, you're essentially spending most of each day in a high-hepcidin state — the precise condition that prevents iron from being absorbed.

This is backed by research. A landmark study published in The Lancet Haematology found that iron absorption was significantly higher in women who took iron on alternating days compared to those who took it every day and even higher than twice-daily dosing. The every-other-day group absorbed more iron total, even though they were taking fewer doses.

The mechanism is elegant: skipping a day allows hepcidin to clear, so when you take your next dose, the gate is open and absorption is maximized.

The Every-Other-Day Protocol

Based on the current evidence, here's what I recommend for most patients supplementing for iron deficiency:

Take your iron supplement every other day — for example, Monday, Wednesday, and Friday.

This approach:

• Keeps hepcidin levels from accumulating
• Maximizes absorption with each dose
• Often reduces GI side effects (nausea, constipation, cramping), which are common with daily iron and are a major reason people stop supplementing

If you're working to replenish severely depleted stores, this still works — it just means we may monitor labs a bit more frequently to track progress.

Coffee, Tea, and the Absorption Problem

Timing matters just as much as frequency.

The tannins and polyphenols in coffee and tea bind to iron in your gut and dramatically reduce how much gets absorbed. Studies suggest these compounds can inhibit non-heme iron absorption by 60–90%, which means taking your supplement right before or after your morning cup may render most of the dose essentially useless.

The same applies to:

• Black tea, green tea, and herbal teas (yes, many herbal teas contain tannins too)
• Calcium-rich foods and dairy (calcium competes with iron for absorption)
• Antacids and proton pump inhibitors (iron requires stomach acid to absorb properly)

The recommendation: Take iron at least 1 hour before or 2 hours after coffee, tea, or calcium-containing foods. Many people find that taking it first thing in the morning (before coffee ) or at bedtime works well.

One More Thing: Add Vitamin C

Vitamin C (ascorbic acid) is iron's best friend. It reduces ferric iron to ferrous iron, the form your intestines can actually absorb. Even a modest amount (100–200 mg) taken alongside your iron supplement can meaningfully boost uptake.

Practical options:

• A small glass of orange juice or another citrus juice
• A 250–500 mg vitamin C supplement taken at the same time
• Foods like strawberries, bell peppers, or kiwi alongside your dose

Your Optimized Iron Routine

To summarize:

When to Seek More Help

If you've been supplementing correctly and your levels still aren't improving, it's worth digging deeper. In functional medicine, we want to understand why iron isn't replenishing — not just throw more iron at the problem.

That might mean evaluating:

• Gut absorption and integrity
• Chronic inflammation driving elevated hepcidin
• Ongoing blood loss that hasn't been addressed
• Whether IV iron infusion is a better fit for your situation

At Nurture MD Health, we look at the whole picture, because fatigue that doesn't resolve with supplements usually has a root cause worth finding.

This content is for educational purposes only and is not a substitute for individualized medical advice. Please consult your healthcare provider before starting or changing any supplement regimen.