What Does a Lack of Manganese Do to Your Body?

While manganese deficiency is very rare in healthy people, it is a crucial trace mineral, and its absence can have notable physiological effects. This essential mineral plays a critical role as a cofactor for enzymes involved in metabolism, bone health, and antioxidant defense, meaning its deficiency can disrupt multiple bodily systems.

Quick Summary

A lack of manganese can impair metabolism, weaken bones, and disrupt hormonal functions, though dietary deficiency is uncommon. Learn the symptoms, causes, and how to maintain adequate intake of this vital trace mineral.

Key Points

• Rare Deficiency: A dietary lack of manganese is extremely uncommon in the general population but can occur in specific medical or genetic circumstances.

• Impaired Metabolism: Deficiency can disrupt carbohydrate, fat, and protein metabolism, leading to impaired glucose tolerance and altered cholesterol levels.

• Weak Bones: As a cofactor for bone-building enzymes, insufficient manganese can cause weak bones and skeletal abnormalities, particularly during development.

• Compromised Antioxidant Defense: Manganese is essential for the antioxidant enzyme MnSOD, so a deficiency can increase cellular vulnerability to oxidative stress.

• Diverse Symptoms: Signs can include skin rashes, mood changes, increased premenstrual pain in women, poor growth, and fertility issues.

• Easy Dietary Fix: A healthy, balanced diet including whole grains, nuts, legumes, and leafy greens provides sufficient manganese for most people.

Understanding the Role of Manganese

Manganese is an essential trace mineral that is only needed by the body in very small amounts, yet it is vital for many physiological processes. It functions primarily as a component or activator of numerous enzymes, which are critical for metabolic reactions throughout the body. Most of the body's manganese is stored in the bones, liver, pancreas, and kidneys.

Cofactor for Vital Enzymes

One of the most important roles of manganese is as a cofactor for manganese superoxide dismutase (MnSOD), a powerful antioxidant enzyme. MnSOD is found in the mitochondria of cells and plays a critical role in neutralizing harmful free radicals, protecting cells from oxidative stress and damage. A deficiency compromises this defense mechanism, increasing cellular vulnerability.

Metabolism and Energy Production

Manganese is essential for the activation of enzymes that help the body process carbohydrates, proteins, and fats. This includes its role in gluconeogenesis—the production of glucose from non-carbohydrate sources, which helps regulate blood sugar levels. When manganese levels are low, these metabolic processes can be altered, leading to impaired glucose tolerance.

Bone Health and Formation

For healthy bone development and maintenance, manganese works in conjunction with other vitamins and minerals. It's required for the synthesis of proteoglycans, which are essential for forming healthy bone and cartilage. Animal studies have shown that manganese deficiency can result in skeletal abnormalities and poor bone formation. While rare in humans, this function is critical, especially during growth.

Reproductive and Hormonal Health

Manganese is involved in reproductive processes and the production of sex hormones. Insufficient manganese levels have been linked to fertility problems. For women, a deficiency can alter mood and increase the severity of premenstrual pain.

Signs and Symptoms of a Lack of Manganese

Because a dietary lack of manganese is so rare, its specific symptoms are not well-established in humans and are often observed in experimental settings or associated with certain medical conditions. However, based on limited human studies and extensive animal research, the following symptoms may manifest from a lack of manganese:

• Impaired Growth: Especially in children, poor or slowed growth can be a symptom.
• Skeletal Defects: Weakened bones and other skeletal abnormalities have been observed.
• Skin Rashes: A temporary skin rash on the torso was observed in adult men experimentally deprived of manganese.
• Altered Glucose Tolerance: The body's ability to process glucose is affected, potentially leading to issues similar to a pre-diabetic state.
• Changes in Cholesterol and Fat Metabolism: Abnormal cholesterol levels can occur.
• Mood Changes: In women, altered mood and increased premenstrual pain have been reported.
• Reduced Fertility: A lack of manganese has been linked to impaired reproductive function.
• Weakened Antioxidant Defense: Lower antioxidant enzyme activity can leave cells more vulnerable to damage.

What Causes a Manganese Deficiency?

For the majority of the population, getting enough manganese from diet is not an issue, as it is found in a wide variety of plant-based foods. The following groups and factors may increase the risk of deficiency:

• Malnutrition or Restricted Diets: Individuals on severely limited or highly processed diets may have insufficient intake.
• Genetic Conditions: Very rare genetic mutations affecting manganese transport can cause severe deficiency symptoms from infancy.
• Chronic Liver Disease: This can impair the body’s ability to regulate manganese levels.
• Digestive Disorders: Conditions like Crohn's disease that affect nutrient absorption can lead to lower manganese levels.
• High Intake of Other Minerals: Excessive intake of iron, calcium, and phosphorus can interfere with manganese absorption.
• Medical Treatments: People on long-term intravenous feeding (parenteral nutrition) may require careful manganese supplementation.

Comparison: Manganese Deficiency vs. Toxicity

It's important to understand the contrast between too little and too much manganese, as both can lead to health problems. While deficiency is rare from diet, toxicity is usually caused by environmental exposure or high-dose supplements.

Feature	Manganese Deficiency	Manganese Toxicity
Causes	Very rare dietary insufficiency; genetic conditions; liver/digestive issues; interactions with other minerals.	Environmental inhalation (welding, mining); contaminated water; high-dose supplements.
Symptom Onset	Gradual and often subtle.	Can be acute with high exposure, or chronic over time.
Neurological Effects	Increased susceptibility to seizures; mood alterations.	Tremors, muscle spasms, impaired motor skills similar to Parkinson's disease.
Growth	Impaired or slowed growth, especially in children.	Can also lead to slowed growth from excessive intake.
Reproductive Health	Impaired fertility; altered hormone levels.	Reproductive problems have also been noted.
Skin	Transient skin rashes.	Skin issues are not a primary feature of toxicity.
Vulnerable Populations	Those with specific medical conditions or genetic mutations.	Industrial workers with high occupational exposure; individuals with liver disease.

How to Ensure Adequate Manganese Intake

Getting enough manganese from a balanced diet is straightforward for most people. Dietary intake is considered safe, as the body tightly regulates its absorption from food.

Dietary Sources of Manganese

Focus on incorporating a variety of the following foods to meet your needs:

• Whole Grains: Brown rice, oatmeal, whole-wheat bread.
• Legumes: Lentils, chickpeas, soybeans, and peas.
• Nuts and Seeds: Hazelnuts, pecans, and sesame seeds.
• Leafy Green Vegetables: Spinach and kale are excellent sources.
• Fruits: Pineapple and blueberries.
• Shellfish: Mussels, clams, and oysters are particularly high in manganese.
• Tea: Black tea can contribute significantly to daily intake.

Supplements

Manganese supplements are available, often in multivitamin formulations or standalone products containing manganese sulfate or other forms. However, supplementation should be approached with caution due to the risk of toxicity from excessive intake. It is always best to consult with a healthcare professional before beginning any supplementation, especially since most people already get sufficient manganese from their diet. For those with rare genetic conditions or malabsorption issues, medical supervision is essential.

Conclusion

While a true dietary lack of manganese is a rare occurrence in the general population, its role as a vital cofactor for numerous enzymes means a deficiency can have real physiological consequences. From impacting metabolism and bone health to affecting reproductive and nervous system functions, the mineral's importance far outweighs its small required quantity. For most individuals, maintaining adequate intake is easily achieved through a balanced diet rich in whole grains, nuts, and leafy greens. If you have concerns about your manganese levels or suspect a deficiency due to a specific health condition, consulting a healthcare provider is the best course of action.

Learn more about trace minerals and their functions by visiting the NIH Office of Dietary Supplements.

Frequently Asked Questions

What are the first signs of manganese deficiency?

Since manganese deficiency is rare and its symptoms are not well-established, it is difficult to identify definitive first signs. However, possible indicators noted in studies include a skin rash and lowered serum cholesterol levels.

Is manganese deficiency common?

No, manganese deficiency is extremely rare in humans, especially in healthy individuals with a varied diet. The mineral is widely available in many common foods, and the body has a robust regulatory system.

What medical conditions increase the risk of manganese deficiency?

Conditions that may increase the risk of deficiency include genetic mutations affecting manganese transport, chronic liver disease, and digestive disorders that affect nutrient absorption, such as Crohn's disease.

Can a vegetarian or vegan diet cause a lack of manganese?

No, it is highly unlikely. Manganese is most abundant in plant-based foods such as nuts, legumes, whole grains, and leafy greens. Vegetarians often have higher manganese intake than those on Western diets.

How is a manganese deficiency diagnosed?

Diagnosing a manganese deficiency is complex. While blood tests measure manganese levels, they may not accurately reflect long-term status. A doctor will typically evaluate symptoms, dietary history, and may order tests to measure red blood cell manganese or enzyme activity if a deficiency is suspected.

What happens to the bones with low manganese?

Since manganese is crucial for bone and cartilage formation, low levels can lead to weakened bones, poor bone mineralization, and skeletal defects. This has been consistently observed in animal studies of manganese deprivation.

Is it better to get manganese from food or supplements?

For most people, getting manganese from food is the safest and best way to meet needs. The body regulates absorption from food, while high-dose supplements can lead to toxicity. Supplements should only be taken under a doctor's guidance.