Molybdenum: Health Effects, Deficiency and Toxicity
Molybdenum is an essential trace mineral that helps the body to break down proteins and certain toxic substances including alcohol. Some experts, therefore, believe it plays a major role in detoxification processes. Molybdenum is easily absorbed from the diet but most of it (60-90%) is excreted through urine, depending on its status in the body. The rest is stored mainly in the liver, kidneys and bones.
The recommended dietary allowance of molybdenum for adults (male and female) is 45mcg per day (pregnant and lactating women need about 50mcg). Most people’s diets provide more than the necessary 45mcg per day. The tolerable upper limit is estimated at 500mcg of molybdenum per day.
Potential Health Effects of Molybdenum
Health effects of molybdenum are not very well explored. However, molybdenum happens to be a cofactor (catalyst) for four human enzymes (sulfite oxidase, xanthine oxidase, aldehyde oxidase and mitochondrial amidoxime-reducing component) that are responsible for catabolizing sulfur-containing amino acids and purines and metabolizing and removing a number of toxic substances including certain drugs and alcohol. Since molybdenum promotes the production of uric acid, it is believed to be a major detoxifying agent.
Some research suggests that molybdenum may also help mobilize iron (even if the iron status is low) and thus prevent anemia. However, too much molybdenum in the diet may actually lead to anemia because it causes copper deficiency, while chronic copper deficiency may in turn result in iron storage disease (too much iron).
Some experts speculate that molybdenum could be used to slow down certain aging processes and even prevent cancer. However, given the current scientific knowledge, these claims appear to be unsubstantiated. But, there is also no evidence to the contrary that excess molybdenum causes cancer. Other potential nutritional benefits of molybdenum including the prevention of dental caries and sexual impotence are being investigated.
Deficiency in molybdenum is very rare. It usually only occurs in people who have been fed intravenously for a long time or those who live in areas with soil and groundwater that are extremely poor in molybdenum. Deficiency symptoms are not very well established but they may include night time blindness, headaches, vomiting, increased heart rate and respiratory rate and mental disturbances.
A normal diet rarely leads to molybdenum overdose. Molybdenum overdose is usually a result of soil and groundwater contamination with industrial pollutants that find their way into people’s diets. Excessive intake of molybdenum can cause copper deficiency, which may lead to anemia. Though not very well documented, other possible symptoms of molybdenum toxicity involve joint and muscle pain, weakness, fatigue, loose stool and weight loss. In cattle, molybdenum has also been linked to fertility problems.
Dietary Sources of Molybdenum
Molybdenum is found in many foods and water. The richest sources of this mineral include legumes (lentils, peas, beans and soybeans), breads and cereals (especially oats and barley), liver, dairy products, nuts and some leafy vegetables. The amount of molybdenum in food depends on the soil content where the plants were grown, including the plants used to feed the animals. The chemistry of water used to water the plants also determines the molybdenum content in foods.
In addition, this mineral is available in supplement form. However, because too little is known about potential health benefits and risks of molybdenum, most doctors do not recommend supplementation.