Minerals Part VII: Manganese, Molybdenum and Chromium

Who has ever heard of manganese, molybdenum or chromium? These substances are also found in our food and play important roles in our bodies. This is remarkable because all three elements are trace elements rather than bulk elements and are only needed in small quantities on a daily basis. Nevertheless, the necessity of a regular supply of all three substances is undisputed, which is why manganese, molybdenum and chromium are considered essential for our body.

Here are the facts-to-go for quick readers!

Chromium, molybdenum and manganese at a glance:

  • Nuts, legumes and wholemeal products are particularly rich in manganese. A daily intake of two to five milligrams is recommended.

Manganese is mainly found in plant sources

In order to take in the daily amount of two to five milligrams of manganese prescribed by the German Nutrition Society, you can fall back on various sources of manganese. Nuts, legumes and wholemeal products are particularly rich in manganese, but animal sources such as meat, fish or milk also contain the element, albeit in small amounts. For example, 30 grams of walnuts contain one milligram, while one kilogram of fish contains three milligrams of manganese. The metabolism of manganese is still partly unclear and little researched. However, the majority of manganese is stored in the bones. It is also important to know that only a small part of the ingested manganese can actually be absorbed in the small intestine. In addition, it seems that iron and manganese have a negative influence on each other’s absorption and metabolism and hinder each other.

Manganese primarily activates enzymes

Currently, three enzymes that depend on the cofactor manganese are known. Although manganese also occurs as a cofactor in a large number of other enzymes, it can be replaced there by other substances in a function-preserving manner. In this way, manganese is particularly involved in carbohydrate and amino acid metabolism. Specifically, it supports gluconeogenesis and urea formation. In addition, manganese plays a role in bone metabolism that should not be underestimated, especially in bone growth. The antioxidant effect against free radicals, the help in the synthesis of cholesterol and triglycerides as well as the participation in the release of catecholamines are also remarkable.

A manganese deficiency has no consequences

Although manganese must also be consumed in sufficient amounts every day, there are currently no known deficiency symptoms in humans due to a manganese intake that is too low. A manganese deficiency can only be described experimentally, whereby the symptoms are difficult to recognise. The reason for this is that manganese deficiency is accompanied by other deficiencies. The consequences of manganese deficiency in animals have been described so far, including CNS disorders and skeletal changes.

If a human actually ingests too much manganese, no toxic effects are to be expected.

Molybdenum is widespread in foods

Let us now move from manganese to molybdenum. The substance sounds unfamiliar in the same way, but also with regard to this essential trace element, the German Nutrition Society recommends a daily intake of 50 to 100 micrograms. The advantage is that this element is found in almost all foods. Nuts, cereals and pulses are particularly rich sources. For example, 100 grams of peanuts contain 43 micrograms of molybdenum. In the body itself, molybdenum is not only found in the skeleton, but also in great numbers in the liver and kidneys. Molybdenum is absorbed in the small intestine with strong variations in absorption. Here the rate ranges from 35 to 90 %. It should be noted, however, that little is known about the metabolism of molybdenum either.

Molybdenum is significantly involved in three important enzymes

Molybdenum is of great importance for three enzymes. Through these enzymes, molybdenum indirectly participates in the following functions: purine metabolism (degradation of GMP and AMP), detoxification of various metabolites, and degradation of catecholamines and sulphur-containing amino acids. As a result, it can be stated that molybdenum is involved in various degradation and detoxification reactions.

Molybdenum deficiency is very rare

In healthy people, a molybdenum deficiency can be ruled out. Only once has a molybdenum deficiency been detected. However, this was a seriously ill patient who had been fed parenterally for 18 months. Thus, a molybdenum deficiency is almost unlikely, as it is hardly possible to develop one. A toxic effect in case of overdose is also to be classified as low. In addition, there are no known effects of a permanently increased intake of molybdenum. Effects on copper metabolism or uric acid levels have only been observed in animal experiments.

Chromium is found in offal, grains, vegetables and nuts.

Finally, let’s take a look at chromium. As already mentioned, chromium is also a trace element and should be ingested in a daily dose of 30 to 100 micrograms according to the German Nutrition Society. Important sources of chromium are offal such as liver and kidney, but also vegetables, nuts and cereals. Tomatoes, for example, contain a relatively large amount of chromium at 20 micrograms per 100 grams. Other components of food are also involved in the absorption of chromium in the small intestine. Above all, amino acids and ascorbic acid promote absorption. Phytates and zinc, on the other hand, have an inhibiting effect.

Little information about the function of chromium

The current state of science with regard to chromium and its function in our body is rather limited. It has been proven that chromium is present in a so-called glucose tolerance factor that supports glucose uptake into muscle and fat cells. In this respect, chromium plays a role in the signal transmission of insulin.

Chromium deficiencies are very rare and overdoses are only relevant in occupational medicine

To date, no real chromium deficiencies have been documented. Only when a sick patient was fed parenterally over a longer period of time and no chromium was substituted, was there evidence of a deficiency. Due to the already known function of chromium as part of a glucose tolerance factor, a deficiency leads to so-called hyperglycaemia (blood sugar level too high). The metabolic situation is then comparable to that of a diabetic. Cholesterol and triglyceride levels also rise pathologically.

If chromium is consumed in high amounts, no effects can be observed even with a regular daily intake of up to one milligram. However, high chromium exposure is relevant in industry. Especially in areas where materials containing chromium are worked with, acute symptoms such as dermatitis can occur. Furthermore, an increased risk of lung cancer cannot be ruled out.

Text sources:

(1) https://www.dge.de/wissenschaft/referenzwerte/kupfer-mangan-chrom-molybdaen/

(2) Niestroj, Practice of Orthomolecular Medicine, 2nd edition, 2000

(3) Schuchardt and Hahn, Importance of the trace elements chromium, manganese and molybdenum in human nutrition, 2011.

(4) Biesalski et al, Pocket Atlas of Nutrition, 8th edition, 2020.

Image sources:

(5) https://unsplash.com/s/photos/nuts