Interaction of manganese with other micronutrients (vital substances):
Calcium
According to several studies, calcium supplementation at 500 mg/day results in decreased bioavailability of manganese, with calcium phosphate and carbonate having the greatest effect and calcium from milk having the least effect; some other studies showed only minimal effects of calcium supplementation on manganese metabolism.
Magnesium
Manganese absorption is decreased with magnesium supplementation of about 200 mg/day.
Phosphate
Dietary phosphates, such as from cured meats, processed cheese, and soft drinks, impair intestinal absorption of manganese.
Iron
There is mutual inhibition of absorption of manganese and iron → iron and manganese compete for the same absorption and transport mechanisms, for example, the divalent metal transporter-1 (DMT-1).
- Manganese absorption from a meal decreases with increasing dietary iron content because DMT-1 expression is downregulated in enterocytes (cells of the small intestinal epithelium)
- According to Davis and Greger (1992), iron supplementation-60 mg/day for 4 months-is associated with decreased serum manganese levels and reduced manganese-dependent superoxide dismutase (MnSOD) activity in leukocytes (white blood cells), indicating a decreased manganese status
- Individual iron supply is a major factor influencing manganese bioavailability. If iron deficiency is present, manganese absorption may be increased 2-3-fold due to increased expression of DMT-1 in enterocytes. “Full iron stores” – measurable by serum ferritin (iron storage protein) levels – on the other hand, are associated with a decrease in intestinal manganese uptake – due to downregulation (downregulation) of cellular DMT-1 synthesis. In light of the fact that higher iron stores are generally detectable in men compared to women, men generally reabsorb less manganese than women.
Cobalt
Cobalt and manganese interfere with each other’s intestinal absorption because both transition metals use the DMT-1.
Phytic acid, oxalic acid, tannins.
Phytates from cereals, legumes, etc., oxalates, for example, from cabbage vegetables, spinach and sweet potatoes, and tannins from tea reduce the bioavailability of manganese.
Further
In addition, an excessive intake of dietary fiber, of the trace elements cadmium and copper, of refined carbohydrates such as industrial sugar and white flour products, as well as increased alcohol consumption also lead to reduced manganese absorption. Similarly, the use of certain medications, such as magnesium-containing antacids (neutralizing stomach acid), laxatives (laxatives), and antibiotics, is associated with impaired intestinal manganese absorption once they are taken together with Mn-containing foods or supplements.
In contrast to the factors listed above, milk increases the bioavailability of manganese.