MANGANESE

Description

Manganese is an essential constituent of several enzymes. It plays a role in the development of the brain and is involved in the synthesis of bone and cartilage and in regulating blood clotting. It is involved in the formation of thyroid hormones, dopamine, melanin, fatty acids, cholesterol and urea. Manganese also participates in the metabolism of carbohydrates to produce energy.

The body stores between 10 and 20 mg of manganese which is concentrated mainly in the liver, pancreas and kidneys.

Sources

Nuts, legumes, spinach, pineapple, small fruits, raisins, whole grain bread and cereal and crustaceans are good sources of manganese. It is also found in tea and coffee.

Approximate manganese Content
 Food  Portion  Content
 Brown rice, cooked 250 mL 1.77 mg
 Chickpeas 250 mL 1.69 mg
 Clams 85 g 0.85 mg
 Hazelnuts 28 g 1.75 mg
 Lentils 250 mL 0.98 mg
 Oat bran, cooked 250 mL 2.11 mg
 Pine nuts 28 g 2.50 mg
 Food  Portion  Content
 Pineapple 250 mL 1.44 mg
 Raisins 250 mL 0.43 mg
 Raspberries 250 mL 0.82 mg
 Spinach, cooked 250 mL 1.68 mg
 Strawberries 250 mL 0.64 mg
 Whole wheat bread 1 slice 0.60 mg
 Whole wheat flour 250 mL 4.56 mg

Vitamin C increases the absorption of manganese, whereas iron, lactose and fibre decrease its absorption.

Adequate intake (AI)

AI is the recommended average daily nutrient intake based on estimates of nutrient intake by groups of healthy people.

Manganese Requirements
 Age  Men   Women 
 1-3 years 1.2 mg 1.2 mg
 4-8 years 1.5 mg 1.5 mg
 9-13 years 1.9 mg 1.6 mg
 14-18 years 2.2 mg 1.6 mg
 Age  Men   Women 
 19-50 years 2.3 mg 1.8 mg
 > 50 years 2.3 mg 1.8 mg
 Pregnancy   +0.2 mg
 Breastfeeding   +0.8 mg

This is roughly what a normal well-balanced diet provides.

Deficiency

No cases of manganese deficiency have been documented in humans since it is easily available in foods throughout the world. Furthermore, magnesium can substitute for manganese in many of its functions.

Manganese deficiency has, however, been observed in a number of animal species. Symptoms include skeletal abnormalities, skin inflammation, altered lipid metabolism, nausea, vomiting and impaired growth.

Toxicity

Manganese toxicity is rare. It is caused by environmental exposure to inhaled manganese and is characterized by convulsions, delirium, hallucinations, parkinsonian syndrome, iron deficiency and reproductive problems.

Supplements

Since manganese is commonly found in the foods we eat, supplements are not necessary.

Watch what you eat. Diet has a significant impact on health!