The Importance of Nickel in the Human Body

December 17, 2025 •

3 min read

Although the precise biological functions of nickel in humans are not fully understood, research indicates this trace element plays a role in key processes such as hormone regulation and iron absorption. Present in very small amounts, the importance of nickel in the human body is subtle but significant for overall health.

Quick Summary

A trace mineral needed in minuscule amounts, nickel aids in iron absorption, hormone production, and enzyme activation within the body. Sufficient dietary intake is crucial for these functions, though deficiency is rare with a balanced diet. High intake levels can cause toxicity or allergic reactions.

Key Points

Trace Mineral: Nickel is a trace mineral that is required by the human body in very small amounts for proper functioning.
Cofactor for Absorption: It acts as a cofactor that aids in the body's absorption of iron from the digestive tract, helping prevent iron-deficiency anemia.
Enzyme and Hormone Regulation: Nickel is involved in the metabolism of several hormones, including adrenaline and prolactin, and activates certain enzymes vital for breaking down glucose.
Supports Cellular Health: Research suggests nickel helps maintain the structural integrity of DNA and RNA and is involved in cell membrane stability.
Sources and Balance: Nickel is found in plant-based foods, such as nuts, legumes, and whole grains, and a balanced diet typically provides sufficient amounts.
Low Risk of Deficiency: Due to the small quantity needed and widespread presence in food, nickel deficiency is rare in humans, though conditions like malabsorption can be a factor.
Toxicity and Allergies: Excessive exposure, primarily in industrial settings, can cause toxicity. Furthermore, nickel is a common allergen, causing contact dermatitis in sensitive individuals.

The Essential Functions of Nickel

While most famously known for its industrial uses, nickel is also a vital trace mineral for human health, required in very small, or 'nano,' quantities. Its precise functions are still under investigation, but research has uncovered several critical roles within the body's complex biochemical systems.

Role in Iron Absorption

One of nickel's most well-documented functions is its involvement in the absorption of iron from the diet. It acts as a cofactor in this process, meaning it assists enzymes responsible for utilizing and breaking down other nutrients. This is particularly important for preventing iron-deficiency anemia, as nickel helps the body make effective use of the iron it consumes. The interaction between nickel and iron is so pronounced that individuals with iron deficiency may absorb more nickel from their diet.

Supporting Hormone and Enzyme Activity

Nickel has been shown to influence the metabolism of several hormones, including adrenaline, aldosterone, and prolactin. Aldosterone, for example, is critical for regulating blood pressure and salt-water balance. Prolactin, involved in breast milk production, is also influenced by nickel concentrations. Additionally, nickel serves as a cofactor for several enzymes, playing a part in metabolic processes and the breakdown of glucose.

DNA and Cell Membrane Stability

Studies also suggest that nickel plays a role in maintaining the structural integrity of both DNA and RNA within our cells. By influencing nucleic acids, nickel contributes to overall genetic stability and cellular health. Furthermore, it is involved in preserving the integrity of cell membranes, which is essential for proper cellular function and communication.

Sources of Dietary Nickel

The body’s minimal requirement for nickel is typically met through a varied diet. Plant-based foods are generally the richest source, although the nickel content can vary depending on the soil where they are grown.

Here is a list of common dietary sources of nickel:

Nuts and Seeds: Hazelnuts, almonds, cashews, sunflower seeds
Legumes: Lentils, peas, and soybeans
Whole Grains: Oats, whole-wheat products, and buckwheat
Vegetables: Spinach, broccoli, and lettuce
Cocoa Products: Dark chocolate and cocoa powder
Seafood: Shellfish like oysters and mussels
Other: Coffee, tea, and licorice

Nickel Deficiency vs. Toxicity

Because the human body needs so little nickel, deficiencies are rare and most people get enough from their diet. However, certain conditions like intestinal malabsorption or excessive sweating could potentially lead to lower levels. Conversely, excessive exposure, particularly in industrial settings or through inhalation, poses significant health risks.

Comparison of Nickel Deficiency vs. Toxicity


Feature	Nickel Deficiency	Nickel Toxicity (Acute)
Cause	Extremely low intake, intestinal malabsorption, certain diseases, or high-level sweating	High-dose ingestion, inhalation (e.g., nickel carbonyl), or industrial exposure
Associated Symptoms	Rare in humans; potential for impaired growth, anemia, reproductive issues, or bone abnormalities seen in animal studies	Nausea, vomiting, diarrhea, headaches, abdominal pain, and vertigo
Long-Term Effects	Poorly studied in humans; animal studies suggest growth and reproductive issues, altered glucose metabolism, and compromised liver function	Chronic respiratory problems, dermatitis, and an increased risk of certain cancers (lung, nasal) with long-term exposure
Diagnosis	Blood or urine tests, although deficiency is rarely the cause of health issues	History of exposure, followed by blood or urine analysis to confirm high levels
Treatment	Dietary changes to include more nickel-rich foods; supplementation under medical guidance in rare cases	Removal from the source of exposure, decontamination, and supportive care; chelation therapy for severe cases

Conclusion: A Delicate Balance

Nickel is a trace element with subtle yet important roles in human health, contributing to enzyme function, iron absorption, and cellular stability. While most people easily meet their minimal needs through a balanced diet, it is a compound where the amount is critical. Low absorption makes deficiency unlikely, while excess can cause toxicity, particularly through environmental or industrial overexposure. The key is maintaining a healthy dietary balance to support these functions without risking harm. For those concerned about allergies or exposure, awareness of common sources, from food to everyday items, is important. For more information on the toxicology of nickel, visit the NCBI Bookshelf.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional for diagnosis or treatment.

Frequently Asked Questions

Nickel is a trace element because the human body needs it in extremely small, or 'nano,' quantities, which are much lower than the amounts required for major minerals like calcium or potassium.

One of nickel's main roles is acting as a cofactor that assists with the absorption of iron from the diet. This function is crucial for preventing iron-deficiency issues like anemia.

No, nickel deficiency is very rare in humans because our bodies need such tiny amounts. A varied and balanced diet is typically sufficient to meet this need.

Good dietary sources of nickel include nuts (hazelnuts, cashews), seeds, legumes (lentils, soybeans), whole grains (oats), cocoa products, and some vegetables like spinach.

Yes, excessive exposure to nickel can be harmful. Inhalation or high-dose ingestion can cause toxicity, and long-term exposure may increase the risk of certain cancers. Nickel is also a common allergen that can cause skin rashes.

Nickel allergy is a common allergic reaction, often caused by skin contact with nickel-containing items like jewelry or certain foods. It can cause a localized, itchy, and erythematous rash.

Unless advised by a healthcare professional, you should not take a nickel supplement. Deficiency is rare, and the risk of toxicity or allergic reaction from over-supplementation is a concern.