What is the Most Absorbable Form of Manganese?

Research indicates that humans absorb only a small percentage—approximately 1-5%—of the manganese consumed from food. This limited absorption rate means that the form of manganese you choose in a supplement is critical for effectiveness. Understanding what is the most absorbable form of manganese can help ensure your body receives this essential trace mineral efficiently. This guide explores the different types of manganese supplements and their bioavailability.

Quick Summary

Chelated forms, such as manganese bisglycinate, are more bioavailable and have superior absorption rates compared to poorly absorbed inorganic salts like manganese sulfate. The best choice depends on individual needs, with gentle chelated versions offering optimal uptake. Factors including iron status and dietary components also influence absorption efficiency.

Key Points

• Chelated is superior: Chelated forms, like manganese bisglycinate, are significantly more absorbable and bioavailable than inorganic salts.

• Inorganic forms absorb poorly: Manganese sulfate and manganese oxide have poor solubility and absorption, making them ineffective for correcting deficiencies.

• Bisglycinate is highly efficient: Bound to the amino acid glycine, manganese bisglycinate uses the body's amino acid transport systems for superior cellular uptake.

• Consider dietary factors: High calcium, iron, and fiber can inhibit manganese absorption, so timing and food choices matter when taking supplements.

• Choose gentle options: For those with sensitive digestion, chelated forms like bisglycinate are gentle on the stomach and less likely to cause irritation.

Understanding Manganese Absorption

Manganese is an essential trace mineral involved in numerous bodily functions, including metabolism, bone formation, and enzyme activation. However, the human body is not very efficient at absorbing it from the gastrointestinal tract. Several factors play a role in how well manganese is absorbed:

• Active transport and passive diffusion: Manganese absorption in the small intestine occurs through both active transport and passive diffusion. The amount of manganese absorbed is highly regulated by the body, with higher absorption occurring during times of low intake.
• Competition with other minerals: Manganese and iron share the same transporter protein (Divalent Metal Transporter 1 or DMT1) in the intestine, which means high iron intake can reduce manganese absorption, and vice versa. Women, who often have lower iron stores, tend to absorb manganese more efficiently than men.
• Dietary inhibitors and enhancers: Certain dietary components can hinder absorption. For example, high intakes of calcium, phosphorus, phytates, and dietary fiber can reduce the uptake of manganese. In contrast, some evidence suggests Vitamin C may aid absorption.

Chelated vs. Inorganic Manganese

Supplement manufacturers offer manganese in various forms, broadly categorized as chelated or inorganic. The primary difference lies in their chemical structure, which dictates how easily the body can absorb and utilize the mineral.

Inorganic manganese salts, such as manganese sulfate and manganese oxide, are composed of manganese bonded to inorganic compounds. These forms are typically inexpensive to produce but are not readily soluble in the stomach's acidic environment. As a result, they are poorly absorbed and can cause digestive irritation.

Chelated manganese, on the other hand, consists of a manganese ion bound to an organic molecule, such as an amino acid. This process, called chelation, creates a stable compound that protects the mineral from dietary antagonists and enhances its transport across the intestinal wall. The small amino acid molecule, like glycine, acts as a vehicle, allowing the manganese to be absorbed more efficiently via the body's amino acid transport systems.

Comparison of Manganese Supplement Forms

Form	Bioavailability	Stomach Gentleness	Primary Use	Notes
Bisglycinate (Chelated)	High	Excellent	Deficiency correction, daily support	Bound to amino acids for optimal absorption.
Gluconate (Chelated)	Good to High	Good	Supplementation	Highly soluble and easily absorbed.
Citrate (Chelated)	Good	Can be laxative at higher doses	Supplementation	Absorbed better than inorganic forms.
Sulfate (Inorganic)	Poor	Can cause irritation	Cost-effective formulations	Poorly absorbed; requires higher doses.
Oxide (Inorganic)	Very Poor	Can cause irritation	Not recommended for supplementation	High elemental concentration, but extremely low bioavailability.

The Most Absorbable Form: Manganese Bisglycinate

Based on the evidence, chelated manganese bisglycinate stands out as the most absorbable and best-tolerated form of manganese. This form is created by binding manganese to two glycine molecules. This amino acid chelate structure offers several advantages:

• Increased stability: The glycine molecules protect the manganese from premature breakdown in the stomach, ensuring it reaches the small intestine intact for optimal absorption.
• Enhanced cellular uptake: Once in the small intestine, the bisglycinate molecule is recognized and transported by the body's natural dipeptide absorption sites, allowing for more efficient entry into the bloodstream compared to inorganic salts.
• Reduced digestive side effects: The gentle nature of the bisglycinate chelate means it is less likely to cause stomach upset or digestive issues, even at higher doses.

Other Bioavailable Manganese Forms

While bisglycinate is often cited for superior bioavailability, other chelated forms also offer good absorption profiles:

• Manganese Gluconate: This form is highly soluble and a preferred choice over basic manganese salts due to its good bioavailability. It is often found in multi-mineral supplements.
• Manganese Citrate: Another chelated option, manganese citrate is soluble and offers better absorption than inorganic forms. It may, however, have a mild laxative effect at higher doses.

Factors Affecting Manganese Absorption

Beyond the form of manganese, other physiological and dietary factors influence how much of the mineral your body ultimately absorbs. These factors highlight why a holistic approach to nutrition is important when supplementing.

1. Iron status: Iron-deficient individuals absorb more manganese, potentially due to shared transport pathways. Conversely, excess iron can limit manganese absorption. This delicate balance is a prime example of mineral interaction.
2. Dosage size: Absorption efficiency is inversely related to dose size. Taking a large single dose results in a lower percentage of absorption compared to smaller, divided doses throughout the day.
3. Overall mineral status: The body's homeostatic mechanisms adapt to maintain balance. If manganese levels are high, absorption from the gut is reduced, and elimination via bile increases.
4. Dietary components: High intake of calcium, phosphorus, and fiber can decrease manganese uptake. Taking your supplement with a meal can improve absorption for many forms, but it's wise to separate it from high-fiber meals or high-dose calcium or iron supplements.

Which Manganese Supplement Should You Choose?

For those looking for the most efficient and gentle way to supplement manganese, the evidence clearly points toward a chelated form like manganese bisglycinate. Its enhanced stability and targeted absorption mechanism make it the optimal choice for correcting a deficiency or ensuring adequate daily intake without digestive distress. While other chelated forms like gluconate and citrate are also good, bisglycinate offers superior performance. Poorly absorbed inorganic salts like sulfate should be avoided for effective supplementation.

When selecting a supplement, prioritize products that list a chelated form of manganese. Read the label carefully to confirm the specific form used. For those with iron deficiency, be mindful of the interaction between iron and manganese absorption, and consider consulting a healthcare provider for personalized advice.

Conclusion

In conclusion, the most absorbable form of manganese for supplementation is a chelated mineral, with manganese bisglycinate offering the highest bioavailability and best tolerability. Inorganic manganese forms like sulfate and oxide are poorly absorbed and are not recommended for effective supplementation. By choosing a high-quality chelated supplement, considering dietary interactions, and managing dosage, you can maximize your body's utilization of this vital trace mineral. Understanding the nuances of mineral absorption empowers you to make better health decisions.

Learn more about manganese from the National Institutes of Health Office of Dietary Supplements.

Frequently Asked Questions

Are all manganese supplements equally effective?

No, the effectiveness of manganese supplements varies widely based on their form. Chelated forms, such as bisglycinate and gluconate, are more absorbable than inorganic salts like manganese sulfate and oxide.

Why is chelated manganese better absorbed?

Chelated manganese is bound to an organic molecule, often an amino acid like glycine. This protects the mineral during digestion and allows it to be transported more efficiently across the intestinal wall using the body's amino acid transport systems.

What is the bioavailability of manganese sulfate?

Manganese sulfate is one of the more common but poorly absorbed forms of manganese. Due to its low bioavailability, higher doses are often required to achieve a therapeutic effect.

Does iron intake affect manganese absorption?

Yes, iron can significantly affect manganese absorption because both minerals share a common transport pathway in the intestines. High iron intake can decrease manganese absorption, and low iron status can increase it.

How should I take my manganese supplement for best absorption?

For best absorption, take a chelated form like manganese bisglycinate. Avoid taking it at the same time as high-dose calcium or iron supplements. Split larger doses throughout the day to maximize absorption.

Can I get enough manganese from food alone?

While many foods like nuts, whole grains, and leafy greens contain manganese, the body typically absorbs a very low percentage of it from dietary sources (1-5%). Supplementation with a bioavailable form may be necessary to correct a deficiency.

Which forms of manganese are gentle on the stomach?

Chelated forms like manganese bisglycinate are known for being gentle on the stomach and are less likely to cause digestive issues compared to harsher, poorly absorbed inorganic salts.