Everything You Need to Know About Iron Deficiency and Absorption
- alissa089
- Sep 22, 2025
- 10 min read
The Iron Guide: Foods, Supplements, and Smart Strategies
🍎 FUN FACT … cooking in a cast-iron skillet can actually increase the iron content of your food, especially when cooking acidic foods like tomato sauce!
This month, we’re diving into iron deficiency, one of the sneakiest and most overlooked nutrition issues out there. Iron is like your body’s behind-the-scenes MVP, helping your brain stay sharp, your energy levels steady, and keeps your muscles moving. It also powers hemoglobin, a little protein taxi that shuttles oxygen all over your body. When iron runs low, you don’t just feel “a little tired”, you can feel totally zapped, foggy, and off your game. As a Registered Dietitian, I often see symptoms being brushed off or mistaken for everyday burnout. Add in the overwhelming, often confusing advice floating around about iron and supplements, and it’s no wonder so many people feel stuck. The good news is, iron deficiency is fixable! I have pulled together evidence-based information that you can use to go from dragging your feet to feeling like yourself again!
✔️Self-Quiz Check: Are You at Risk?
There are certain factors that can increase your risk of iron deficiency. Answer yes or no to the following questions:
Do you eat little or no red meat, or mostly follow a vegetarian/vegan diet?
Are you having regular periods, going through perimenopause with irregular cycles, or still pre-menopausal?
Do you do a lot of endurance exercise (like running, cycling, or high-intensity training) several times per week?
Do you often feel fatigued, dizzy, or unusually low in energy?
Do you frequently skip meals or have trouble eating enough iron-rich foods each day?
Let’s Dive Into This Topic, and Define Iron Deficiency
Iron deficiency is a health condition characterized by insufficient iron stores in the body. It generally occurs in two stages:
Iron depletion: In this stage, your iron intake or absorption is not enough to meet your body’s needs. Iron stores (primarily in the liver, spleen, and bone marrow) start to decline, but your red blood cell production may still be normal.
Iron deficiency anemia: If iron depletion continues, your body’s ability to produce hemoglobin and healthy red blood cells becomes impaired. This leads to iron deficiency anemia, where there is not enough hemoglobin to carry adequate oxygen to your tissues and organs.
Iron deficiency can be caused by:
Low intake or poor absorption; e.g., vegetarian/vegan diets, GI disorders, certain medications.
Higher iron needs; e.g., pregnancy, adolescence, menstruation, or perimenopause.
Blood loss; e.g., heavy periods, GI bleeding, surgery, frequent donation.
❓Did You Know: Iron deficiency is a common health condition amongst Canadians, with 10.5% of the population experiencing iron deficiency at any point in their life.
🩸Determining Iron Deficiency Through Bloodwork, Knowledge is Power
When iron deficiency is suspected, two main blood tests are commonly used:
A. Serum ferritin
Ferritin is a protein that stores iron in your cells. The serum ferritin measured in blood reflects your body’s iron stores. Low ferritin levels indicate depleted iron stores and a higher risk of developing iron deficiency.
B. Complete blood count (CBC)
The CBC includes hemoglobin and hematocrit, which can indicate anemia. Since hemoglobin contains iron, a low hemoglobin level suggests that iron stores are severely depleted and anemia may have developed.
Notes for accuracy:
Ferritin is considered the most sensitive early marker for iron deficiency
Low hemoglobin indicates iron deficiency anemia, which is a later stage after iron stores have been depleted
Blood Marker | Value | Interpretation |
Ferritin | < 30 ug/L | Iron deficiency |
30-50 ug/L | Probable iron deficiency | |
50-199 ug/L | Risk for iron deficiency | |
> 100 ug/L | Normal range | |
Hemoglobin | < 120 g/L | Anemic |
120-160 g/L | Normal range |
Self-Check, Iron Deficiency Symptoms Mapped Out
Symptoms of iron deficiency should never be ignored! If you are experiencing any of the following symptoms, talk to your doctor about getting your bloodwork done to check on your iron levels.
Fatigue and low energy
Pale skin
Dizziness or lightheadedness
Headaches
Hair loss
Cold intolerance
Nail changes
Restless leg syndrome
Well, How Much Iron Should We Be Getting Daily?
Iron requirements differ between age, sex, and life stages for females. Use the chart below to determine how much iron you require in one day.
Age (years) | Females | Males |
14-18 | 15 mg/day | 11 mg/day |
19-50 | 18 mg/day | 8 mg/day |
51+ | 8 mg/day | 8 mg/day |
Pregnancy | 27 mg/day | —- |
Lactation, ages < 19 years | 10 mg/day | —- |
Lactation, ages 19+ years | 9 mg/day | —- |
Top 30 Iron-Rich Food Sources Listed Below 🥩🥚🥬🫘🍗
Foods provide two main types of iron: heme iron, found in animal-based sources (such as meat, poultry, and seafood), which is absorbed more efficiently by the body, and non-heme iron, found in plant-based sources (such as beans, lentils, grains, nuts, and vegetables). Pairing non-heme iron sources with vitamin C-rich foods (like citrus, peppers, or berries) can significantly boost absorption. Below is a chart of common iron-rich foods, organized from highest to lowest iron content, with exact portion sizes and the amount of iron each provides based on the Canadian Nutrient File.
Food | Portion Size | Iron (mg) |
Very High Sources | ||
Pork liver, cooked | 75 g (2.5 oz) | 13.4 mg |
Chicken liver, cooked | 75 g | 9.2 mg |
Oysters, cooked | 75 g | 6.3 mg |
Mussels, cooked | 75 g | 5.0 mg |
Beef liver, cooked | 75 g | 4.8 mg |
Liver pâté, canned | 75 g | 4.1 mg |
High / Good Sources | ||
Enriched infant cereal (dry) | 28 g (≈ 5 Tbsp) | 7.0 mg |
Boiled soybeans | ¾ cup (175 mL) | 6.5 mg |
Lentils, cooked | ¾ cup (175 mL) | 4.9 mg |
Pumpkin seeds / kernels, roasted | ¼ cup (60 mL) | 4.7 mg |
Enriched cold cereal | 30 g | 4.5 mg |
Kidney beans, dark red, boiled | ¾ cup | 3.9 mg |
Blackstrap molasses | 1 Tbsp (15 mL) | 3.6 mg |
Instant/quick oats, enriched, prepared | ¾ cup (175 mL) | 3.5 mg |
Spinach, cooked | ½ cup (125 mL) | 3.4 mg |
Moderate Sources | ||
Refried beans | ¾ cup (175 mL) | 2.7 mg |
Beef, cooked (various cuts) | 75 g (2.5 oz) | 2.4–2.6 mg |
Firm tofu, cooked | 150 g (¾ cup) | 2.4 mg |
Spinach, cooked | ½ cup (125 mL) | 2.0–3.4 mg |
Quinoa, cooked | ½ cup (125 mL) | 1.5 mg |
Eggs (2 large) | 2 eggs | 1.4 mg |
Vitamin C and Iron - The Perfect DUO
Vitamin C is essential for immune health, collagen production, and overall wellness, and it also plays a key role in enhancing the absorption of non-heme iron from plant-based foods. Adults need approximately 90 mg/day for men and 75 mg/day for women, according to the Dietary Reference Intakes (DRIs). Pairing vitamin C-rich foods; like citrus, peppers, and berries with iron-containing plant foods such as beans, lentils, and spinach can significantly improve the body’s iron uptake. Below is a chart of vitamin C-rich foods, organized from highest to lowest content, with exact portion sizes and the amount of vitamin C each provides.
Food | Portion Size | Vitamin C (mg) |
Very High Sources | ||
Guava, raw | 1 fruit (55 g) | 125 mg |
Red sweet pepper, raw | ½ cup (125 mL) | 95 mg |
Kiwi, raw | 1 medium (76 g) | 64 mg |
Orange, raw | 1 medium (140 g) | 53 mg |
Green sweet pepper, raw | ½ cup (125 mL) | 50 mg |
Strawberries, fresh | ½ cup (125 mL) | 45 mg |
Papaya, raw | ½ fruit (140 g) | 45 mg |
Broccoli, cooked | ½ cup (125 mL) | 40 mg |
Brussels sprouts, cooked | ½ cup (125 mL) | 38 mg |
Grapefruit, raw | ½ fruit (123 g) | 38 mg |
High / Good Sources | ||
Mango, raw | ½ fruit (100 g) | 30 mg |
Cauliflower, cooked | ½ cup (125 mL) | 28 mg |
Pineapple, raw | ½ cup (125 mL) | 28 mg |
Cantaloupe, raw | ½ cup (125 mL) | 25 mg |
Kale, cooked | ½ cup (125 mL) | 24 mg |
Potato, baked with skin | 1 medium (150 g) | 22 mg |
Raspberries, raw | 1 cup (250 mL) | 20 mg |
Turning the “Pairing the Iron-Vitamin C Method” into Action
Research suggests that a 2:1 ratio of vitamin C to iron is most effective for improving absorption (for example, 60 mg of vitamin C with 10 mg of iron).
A practical way to achieve this is by pairing iron-containing foods with vitamin C–rich foods at meals. Pairing meals in this way helps overcome dietary inhibitors and supports better iron absorption naturally.
Here are 5 easy examples:
Spinach salad (½ cup cooked, 3.4 mg iron) + ½ cup strawberries (45 mg vitamin C)
Lentil soup (¾ cup cooked, 4.9 mg iron) + ½ cup red bell pepper slices (95 mg vitamin C)
Kidney beans (¾ cup cooked, 3.9 mg iron) + 1 kiwi (64 mg vitamin C)
Tofu stir-fry (150 g firm tofu, 2.4 mg iron) + ½ cup broccoli, cooked (40 mg vitamin C)
Chickpea salad (¾ cup cooked, 2.9 mg iron) + ½ cup pineapple chunks (28 mg vitamin C)
Give Iron and Calcium Their Own Spotlight
Calcium is essential for strong bones and overall health, but it can compete with iron for absorption. To get the most from your iron-rich foods, try to enjoy calcium-rich foods 1-2 hours apart from iron sources. Think of it as giving each nutrient its own moment to shine!
Practical examples of calcium-rich foods to time wisely:
Dairy: milk, cheese, yogurt, cottage cheese
Fortified alternatives: soy milk, almond milk, orange juice with added calcium
Fish & seafood: canned salmon (with bones), sardines
Other sources: tofu prepared with calcium, fortified breakfast cereals, almonds, chia seeds
How to Navigate Iron Supplements?
Iron supplements come in many forms, strengths, and brands, which can make choosing the right one overwhelming. Effectiveness depends on elemental iron content, absorption, tolerability, and dosing frequency. The chart below organizes supplements from strongest to lowest recommended options, with practical brand examples to make navigating choices easier.
Supplement Type / Brand Examples | Elemental Iron per Dose | Absorption Rate | GI Side Effects | Dosing Frequency | Pros / Cons |
FeraMAX® Pd Therapeutic 150 (FeraMAX® Pd Therapeutic 150 capsule, FeraMAX® Pd Powder 15) | 150 mg (capsule), 15 mg (powder) | ~20–25% | Lower | Once daily | High-dose, once-daily; PDIC formulation is gentler on the stomach; vegan-certified; free from gluten, lactose, alcohol; no metallic taste; can be taken with or without food. Cons: higher cost; powder may require mixing |
Ferrous Fumarate (Palafer 300 mg tablet, Fer-In-Sol syrup) | ~90 mg | ~20% | Moderate | 2–3 times daily | High elemental iron content; well-tolerated. Cons: may cause GI discomfort |
Ferrous Sulfate (Fer-In-Sol syrup, Life Brand tablet) | ~60 mg | ~20% | Higher | 2–3 times daily | Widely available; cost-effective. Cons: commonly associated with GI side effects |
Ferrous Bisglycinate (Gentle Iron capsules, Active Iron capsules) | ~30 mg | ~25% | Lower | 1–2 times daily | Better tolerated; fewer GI side effects. Cons: higher cost; may require larger volume for desired dose |
Ferrous Gluconate (NovaFerrum YUMMY liquid, Flora Iron+ liquid) | ~30 mg | ~10–20% | Lower | 3–4 times daily | Gentler on stomach; lower risk of side effects. Cons: lower elemental iron; may require higher doses |
Liquid Iron Supplements (Land Art 500 mL, NovaFerrum YUMMY 473 mL) | 10–20% (varies) | ~10–20% | Moderate | 1–2 times daily | Easier to swallow; suitable for those with swallowing difficulties. Cons: can stain teeth; may cause GI discomfort |
My Top Pick? FeraMAX® Pd Therapeutic 150
Why it’s a top choice:
Formulation: Polysaccharide-Iron Complex (PDIC)
Elemental Iron: 150 mg per capsule
Absorption Rate: ~20–25%
Dosage: Once daily
Tolerability: Designed to be gentler on the stomach with reduced GI side effects compared to ferrous salts
Additional Benefits: Vegan-certified, free from gluten, lactose, and alcohol, no metallic taste, can be taken with or without food
FeraMAX® aligns well with Alberta Health Services (AHS) guidelines, which emphasize:
Oral iron therapy is first-line for iron deficiency anemia (IDA)
Typical therapeutic doses are 100–200 mg elemental iron/day depending on individual needs
Intermittent dosing (e.g., every other day) may improve absorption and reduce GI side effects
Supplements should be taken under the guidance of a healthcare provider, paying attention to type, timing, and dose
Top Recommendation for Correcting Iron Deficiency
While several options are effective, Ferrous Fumarate is often clinically recommended for oral iron therapy due to its high elemental iron content and proven efficacy. Brands like Palafer and Fer-In-Sol are widely available in tablet and liquid forms.
Dosage: 100–200 mg of elemental iron/day, divided into 1–2 doses
Duration: Typically 3–6 months after hemoglobin normalizes to replenish iron stores
Tips for Optimal Iron Absorption
Timing: Take on an empty stomach if tolerated; otherwise with a small meal to reduce GI side effects.
Avoid inhibitors: Calcium-rich foods, antacids, tea, or coffee can reduce absorption.
Enhance absorption: Pair with vitamin C-rich foods (citrus, bell peppers, berries).
Monitor levels: Check iron and ferritin periodically to track effectiveness.
Follow AHS advice: Intermittent dosing or spacing from inhibitors can improve absorption and tolerance.
Iron Boost Menu: 3-Day Plan for Energy & Absorption
RECAP … Iron is essential for energy, immunity, and overall health. Pairing iron-rich foods with vitamin C helps your body absorb more iron, while including protein at each meal supports muscle health and satiety. This 3-day menu incorporates iron-rich foods, vitamin C sources, protein, and low-GI starches, following Plate Method portions.
Day 1
Breakfast
2 scrambled eggs
1 cup cooked spinach (6 mg iron)
1 slice whole-grain toast (1 mg iron)
1/2 cup strawberries (50 mg vitamin C)
1 tsp olive oil (for cooking eggs)
Morning Snack
1 small orange (60 mg vitamin C)
15 g pumpkin seeds (1 mg iron)
Lunch
100 g grilled chicken breast (1 mg iron)
1 cup steamed broccoli (1 mg iron, 80 mg vitamin C)
1/2 cup cooked quinoa (1 mg iron)
1 tsp olive oil drizzle
Afternoon Snack
170 g plain Greek yogurt (0.1 mg iron)
1/2 cup raspberries (4 mg iron, 30 mg vitamin C)
1 tsp chia seeds (0.5 mg iron)
Dinner
100 g lean beef (2.5 mg iron)
1 cup roasted Brussels sprouts (3.5 mg iron, 75 mg vitamin C)
1/2 cup cooked sweet potato (1 mg iron)
Day 2
Breakfast
1 cup fortified oatmeal (3 mg iron)
1 boiled egg
1/2 cup blueberries (15 mg vitamin C)
1 tsp flax seeds (0.5 mg iron)
Morning Snack
1 kiwi (70 mg vitamin C)
15 g almonds (1 mg iron)
Lunch
100 g baked salmon (0.5 mg iron)
1 cup sautéed kale (2 mg iron, 80 mg vitamin C)
1/2 cup cooked barley (1 mg iron)
1 tsp olive oil
Afternoon Snack
1/2 cup edamame (2 mg iron)
1/2 cup sliced bell peppers (60 mg vitamin C)
Dinner
100 g turkey breast (1 mg iron)
1 cup roasted cauliflower (1 mg iron, 70 mg vitamin C)
1/2 cup lentils (3 mg iron)
Day 3
Breakfast
2 scrambled eggs
1/2 cup black beans (3 mg iron)
1 slice sprouted grain bread (1 mg iron)
1/2 grapefruit (40 mg vitamin C)
Morning Snack
1 small handful dried apricots (1 mg iron)
15 g sunflower seeds (1 mg iron)
1/2 cup orange segments (60 mg vitamin C)
Lunch
100 g grilled chicken (1 mg iron)
1 cup steamed broccoli (1 mg iron, 80 mg vitamin C)
1/2 cup cooked brown rice (0.5 mg iron)
1 tsp olive oil
Afternoon Snack
170 g plain Greek yogurt (0.1 mg iron)
1/2 cup strawberries (25 mg vitamin C)
1 tsp pumpkin seeds (0.5 mg iron)
Dinner
100 g lean beef (2.5 mg iron)
1 cup roasted asparagus (1 mg iron, 60 mg vitamin C)
1/2 cup cooked chickpeas (2 mg iron)
Feeling Iron Overloaded With Info? Winding Down, Below:
Iron is essential for energy, immunity, and overall health; but getting enough isn’t always easy. The good news? With the right foods, smart pairings with vitamin C, and carefully chosen supplements, you can support your iron levels effectively. From leafy greens and beans to lean meats and fortified grains, plus top supplement options like FeraMAX® Pd Therapeutic 150, there are practical strategies to meet your iron needs every day.
Thank you for following along! Don’t forget to subscribe for more nutrition tips and share this newsletter with friends or family who may benefit from boosting their iron and supporting their health.
Xoxo, Healthy U Team
Alyssa Hewson
Elisa Porretta
Alissa Steinberg RD CDE MHSc
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