Should I Take Zinc if I Have Low Iron? A Guide to Proper Supplementation

December 8, 2025 •

4 min read

According to the World Health Organization, iron deficiency anemia is the most common nutritional deficiency globally, and deficiencies in other trace elements like zinc often coexist. This makes it important for individuals with low iron to understand the implications of supplementing zinc, as these two essential minerals can interfere with each other's absorption.

Quick Summary

Zinc and iron supplements should not be taken at the same time, as they can compete for absorption within the body. While both are vital for health, proper timing is necessary to maximize the benefits of each. Consulting a healthcare professional is recommended to determine appropriate dosages and spacing.

Key Points

Consult a Doctor: Always get your iron and zinc levels checked by a healthcare professional before starting supplementation.
Space Your Doses: Take iron and zinc supplements at different times of the day, ideally with a 2–4 hour gap, to prevent them from interfering with each other's absorption.
Choose the Right Form: Certain forms of zinc, like zinc glycinate and picolinate, may have better bioavailability and cause less stomach upset than zinc sulfate.
Combine with Vitamin C: Pair your iron supplement with vitamin C-rich foods or a supplement to enhance iron absorption.
Be Mindful of Inhibitors: Avoid taking zinc or iron supplements with coffee, tea, or high-calcium foods, as these can block mineral absorption.
Avoid Excessive Intake: Do not exceed the tolerable upper intake level of 40 mg of zinc per day to prevent toxicity and copper deficiency.
Address Underlying Causes: Remember that correcting a nutritional deficiency through supplementation is often only one part of the solution; address the root cause with your doctor.

The Interaction Between Zinc and Iron

Zinc and iron are essential trace minerals vital for numerous bodily functions. Iron is crucial for red blood cell formation and oxygen transport, while zinc supports immune function, cell growth, and metabolism. However, when taken simultaneously, these two minerals can compete for absorption in the intestines, particularly at high supplemental doses. This competitive interaction can reduce the bioavailability of both minerals, diminishing the effectiveness of supplementation.

Clinical studies have shown that high concentrations of one mineral can negatively affect the absorption of the other, especially when taken in liquid form on an empty stomach. The issue is most significant when taking high-dose supplements, such as therapeutic iron doses, which can significantly impair zinc uptake. When mixed with food, the inhibitory effect is often reduced or eliminated, but careful timing remains the best practice. For individuals with a diagnosed deficiency in either or both, this interaction means that improper supplementation could hinder treatment progress rather than help.

When to Consider Zinc Supplementation for Low Iron

While having low iron doesn't automatically mean you need zinc, many studies show a high prevalence of coexisting zinc and iron deficiencies, particularly in populations with poor nutritional intake. A healthcare provider may recommend assessing your zinc levels, and if a deficiency is also present, a combined supplementation strategy may be advised.

Exaggerated Symptoms: Research has found that zinc deficiency can worsen the symptoms of iron deficiency, including epithelial problems like glossitis (inflamed tongue) and dermatitis. In such cases, correcting both deficiencies is crucial for symptom relief.
Underlying Issues: Zinc plays a role in iron metabolism and red blood cell production. Correcting a zinc deficiency might indirectly improve the body's overall response to iron therapy by supporting these processes.

How to Properly Take Zinc and Iron Supplements

If you need to supplement both minerals, timing is the most important factor. Spacing out your doses ensures that each mineral is absorbed effectively without interfering with the other. A standard approach is to take them several hours apart. Iron supplements are often recommended to be taken on an empty stomach to maximize absorption, though this can sometimes cause stomach upset. Zinc can be taken with a light meal to improve tolerance if it causes nausea.

Spacing the dose: Aim for a 2–4 hour window between taking your iron and zinc supplements.
Pair with enhancers: Take your zinc supplement with food to reduce nausea. To boost iron absorption, pair it with a vitamin C-rich food or supplement.
Avoid inhibitors: Do not take your zinc and iron at the same time. Also, avoid consuming coffee, tea, dairy products, or high-calcium foods near the time of supplementation, as these can inhibit absorption.

Comparison of Zinc Supplement Forms

When choosing a zinc supplement, the form can influence its bioavailability and potential side effects. Some forms may be better tolerated than others, particularly when managing existing conditions like low iron.


Zinc Form	Bioavailability & Absorption	Side Effects & Tolerability	Considerations	Recommended for
Zinc Gluconate	Good, widely used.	Potentially bitter taste in lozenges, can cause stomach upset.	Common and affordable.	General supplementation, managing cold symptoms.
Zinc Picolinate	Good absorption, some studies suggest higher tissue uptake.	Often well-tolerated with fewer gastrointestinal issues.	May be more expensive, less common in standard stores.	Better tolerability for sensitive stomachs.
Zinc Glycinate	High bioavailability, superior absorption reported in some studies.	Well-tolerated due to chelated form.	Chelated form, often used in high-quality supplements.	Maximizing absorption and minimizing side effects.
Zinc Sulfate	Good absorption, especially in water-soluble forms.	Can cause significant stomach upset and nausea.	More likely to be used for therapeutic doses, but side effects are common.	Short-term therapeutic use under medical supervision.

High-Zinc Intake Risks

While correcting a deficiency is important, excessive zinc intake carries its own risks. The tolerable upper intake level (UL) for adults is 40 mg per day from all sources, and exceeding this can lead to adverse effects.

Copper Deficiency: One of the most notable risks is a potential copper deficiency. High, chronic zinc intake can interfere with copper absorption, leading to a secondary deficiency. Copper is also essential for iron metabolism, so a zinc-induced copper deficiency could ironically worsen your iron status.
Gastrointestinal Issues: Over-supplementation can cause nausea, abdominal cramps, and vomiting.
Reduced Immunity: High doses of zinc over a prolonged period can actually have a negative impact on immune function.

Conclusion

For individuals with low iron, the decision to take zinc requires a thoughtful and informed approach. While concurrent deficiencies are common, taking these minerals at the same time is not recommended due to competitive absorption. The best practice is to consult a healthcare provider to determine if you have a zinc deficiency in addition to low iron. If supplementation is necessary, choose a highly bioavailable form of zinc and strictly space your doses several hours apart to maximize absorption of both minerals. Be mindful of the upper intake levels to avoid risks like copper deficiency and gastrointestinal upset. By following these guidelines, you can safely address multiple deficiencies and support your overall health effectively.

Frequently Asked Questions

Zinc and iron supplements should be taken at different times because they compete for absorption in the intestines. Taking them together, especially in high doses, can decrease the absorption of both minerals, making supplementation less effective.

It is generally recommended to wait at least 2–4 hours between taking your zinc and iron supplements. This time gap allows your body to absorb each mineral separately and more efficiently.

Yes, zinc deficiency can sometimes contribute to iron metabolism issues, and the two deficiencies often coexist. In some cases, a combined deficiency can worsen symptoms, and correcting both may be necessary.

Excessive zinc intake, especially over the long term, can cause nausea, vomiting, headaches, and abdominal cramps. It can also interfere with the absorption of copper, potentially leading to a copper deficiency.

There is no strict rule on which to take first. Some suggest taking iron on an empty stomach and zinc with food to minimize nausea. The most crucial factor is consistently spacing them several hours apart to prevent competitive absorption.

Forms like zinc glycinate or zinc picolinate are often recommended due to their high bioavailability and better tolerability for sensitive stomachs. Zinc sulfate can cause more gastrointestinal distress.

Many people can get sufficient zinc and iron from a balanced diet, which is the preferred method. However, those with deficiencies, restrictive diets, or certain medical conditions may require supplementation under a doctor's supervision.