Deficiency diseases are diseases in humans that are directly or indirectly caused by a lack of essential nutrients in the diet. Deficiency diseases are commonly associated with chronic malnutrition. Additionally, conditions such as obesity from overeating can also cause, or contribute to, serious health problems. Excessive intake of some nutrients can cause acute poisoning.

[edit] Overnutrition

[edit] Metabolic

Obesity is caused by consuming too many calories compared to the amount of exercise the body is performing, causing a distorted energy balance. It can lead to diseases such as cardiovascular disease and diabetes. Obesity is a condition in which the natural energy reserve, stored in the fatty tissue of humans and other mammals, is increased to a point where it is associated with certain health conditions or increased mortality.

The low-cost food that is generally affordable to the poor in affluent nations is low in nutritional value and high in fats, sugars and additives. In rich countries, therefore, obesity is oftentimes a sign of poverty and malnutrition while in poorer countries obesity is more associated with wealth and good nutrition. Other non-nutritional causes for unhealthy obesity included: sleep deprivation, stress, lack of exercise, and heredity.

Acute overeating can also be a symptom of an eating disorder.

Goitrogenic foods can cause goitres by interfering with iodine uptake.

[edit] Vitamins and micronutrients

Vitamin poisoning is the condition of overly high storage levels of vitamins, which can lead to toxic symptoms. The medical names of the different conditions are derived from the vitamin involved: an excess of vitamin A, for example, is called "hypervitaminosis A".

Iron overload disorders are diseases caused by the overaccumulation of iron in the body. Organs commonly affected are the liver, heart and endocrine glands.

[edit] Deficiencies

Disability-adjusted life year for nutritional deficiencies per 100,000 inhabitants in 2002. Nutritional deficiencies included: protein-energy malnutrition, iodine deficiency, vitamin A deficiency, and iron deficiency anaemia.^[1]

     no data      less than 150      150-300      300-450      450-600      600-750      750-900      900-1050      1050-1200      1200-1350      1350-1500      1500-1750      more than 1750

[edit] Proteins/fats/carbohydrates

• Protein-energy malnutrition
  • Kwashiorkor
  • Marasmus
  • Mental retardation^[2]

[edit] Dietary vitamins and minerals

• Calcium
  • Osteoporosis
  • Rickets
  • Tetany
• Iodine deficiency
• Selenium deficiency
• Iron deficiency
  • Iron deficiency anemia
• Zinc
  • Growth retardation
• Thiamine (Vitamin B1)
  • Beriberi
• Niacin (Vitamin B3)
  • Pellagra
• Vitamin C
  • Scurvy
• Vitamin D
  • Osteoporosis
  • Rickets

[edit] Complex disorders

In some cases, eating too much of one thing can induce an apparent deficiency of something else. A common example occurs when livestock eat locoweed: locoweed contains a toxin that inhibits an enzyme, simulating a deficiency of the enzyme.

[edit] Foot notes

[edit] See also

• Avitaminosis
• Malnutrition
• Essential nutrient
• List of ICD-10 codes (E54-E64) -- detailed taxonomy
• Obesity
• Osteoporosis