Like zinc and copper, manganese is a trace element that can profoundly affect bone health. Yet for a long time it was one of the most overlooked nutrients, and to date no RDA for manganese has been established.
One reason cited for this lack of an RDA in the past was that scientists weren’t really sure what people’s typical manganese intakes were. It appears manganese intake can vary widely depending on basic food choices. For example, we now know that intake of manganese is greatly reduced when whole grains are replaced in the diet with foods made from refined flour. This gives us pause because grain products constitute nearly 40% of our daily manganese intake. Beverages (particularly tea) contribute about 20%, and vegetables less than 20%. Other dietary patterns can inhibit the absorption of manganese, such as getting too much calcium, phosphorus, iron, or zinc.
In recent decades research has uncovered the special role manganese plays as a co-factor in the formation of bone cartilage and bone collagen, as well as in bone mineralization. Osteoporotic changes in bone can be brought about by manganese deficiency, which appears to increase bone breakdown while decreasing new bone mineralization. In a Belgian study, blood levels of manganese of severely osteoporotic women were found to be just one-fourth those of non-osteoporotic women their same age. What’s more, of the 25 variables studied, only manganese was significantly different between the two groups. Fortunately, manganese deficiency is relatively easy to address and dietary sources are extremely safe.