Manganese deficiency – symptoms, causes and health effects

Manganese was first isolated in 1774 and was obtained from pyrolusite, a mineral containing manganese dioxide. It is of great importance to humans, although it does not need to be consumed in large quantities. It is involved, amongst other things, in connective tissue, bone health, nutrient metabolism and the protection of cells against oxidative stress. Manganese deficiency is a subject requiring caution, as there is no straightforward set of health effects specific to this element alone.

1. Symptoms of manganese deficiency
2. Causes of manganese deficiency
3. Manganese in food

Symptoms of manganese deficiency

Manganese deficiency is considered rare, and assessing it is not as straightforward as it is for nutrients for which routine laboratory tests are more commonly carried out. The importance of this element stems from its role in normal energy metabolism, maintaining healthy bones, the proper formation of connective tissue, and protecting cells from oxidative stress.

However, symptoms that may suggest nutritional disorders are usually non-specific and can result from many causes, such as an insufficient energy intake, deficiencies in other minerals and vitamins, gastrointestinal diseases, chronic stress, sleep deprivation, or the use of very restrictive diets. For this reason, weakness, fatigue, poor concentration, a deterioration in skin appearance or slower recovery should not automatically be linked to manganese.

If a deficiency is suspected, it is important to assess the entire diet, health status and risk factors, rather than attributing symptoms to a single nutrient. Consultation with a doctor or clinical dietitian is particularly important if symptoms persist for a longer period, if there are coexisting gastrointestinal conditions, or if the person is taking mineral supplements.

Causes of manganese deficiency

Manganese status is influenced not only by its quantity in the diet, but also by its absorption in the gastrointestinal tract, the composition of the overall diet, and the mechanisms regulating its excretion, primarily via bile. The risk of an insufficient intake may be higher among people whose diet is very monotonous, severely restricted, based on a narrow range of foods, or chronically deficient in energy and selected nutrients. Situations involving digestive and absorption disorders, chronic diarrhoea, intestinal diseases, long-term restriction of many food groups, or parenteral nutrition without appropriately selected trace elements may also be significant.

The bioavailability of manganese depends on other dietary components. Some compounds present in food may limit the absorption of certain minerals. A high intake of calcium, phosphorus or iron may, under certain conditions, affect the utilisation of manganese.

Estimated manganese content in some of its sources

Manganese in food

According to the European Food Safety Authority (EFSA), the Adequate Intake (AI) of manganese for adults is 3 mg per day. The main dietary sources of manganese are plant-based foods, particularly whole grains, oats, groats, brown rice, nuts, seeds and pulses, although some amounts can also be found in cocoa, tea and certain leafy vegetables.

"By adding sprouts to your meals, you enrich your diet not only with freshness and plant enzymes, but also with manganese – an element essential for the proper functioning of the skeletal system and energy metabolism." Łukasz Domeracki – Dietitian

In cereal products, the degree of grain refinement is of significant importance, as a large proportion of minerals is found in the outer layers of the grain, which are partially removed during the production of white flour. For this reason, a diet based almost exclusively on white bread, white pasta, sweets and highly processed foods may provide less manganese than a diet containing groats, wholemeal bread, natural cereals, nuts and seeds. It is also important to include a variety of manganese sources in your daily diet, as this ensures you also get fibre, magnesium, zinc, copper, B vitamins and other nutrients that support the overall quality of your diet.

Sources:

• Kippler, M., & Oskarsson, A. (2024). Manganese - a scoping review for Nordic Nutrition Recommendations 2023. Food & nutrition research, 68, 10.29219/fnr.v68.10367. https://doi.org/10.29219/fnr.v68.10367
• Aschner, J. L., & Aschner, M. (2005). Nutritional aspects of manganese homeostasis. Molecular aspects of medicine, 26(4-5), 353–362. https://doi.org/10.1016/j.mam.2005.07.003
• Finley JW, Davis CD. Manganese deficiency and toxicity: are high or low dietary amounts of manganese cause for concern?. Biofactors. 1999;10(1):15-24. doi:10.1002/biof.5520100102