Zinc

December 27, 2011 by  
Filed under Elements

Keywords: Protein synthesis, skin health, fatty acid metabolism, growth, vitamin A metabolism, mental health

Functions

  • Acid/alkaline balance
  • Alcohol detoxification
  • Carbon dioxide transport
  • Collagen synthesis
  • Energy metabolism
  • Growth
  • Haemoglobin
  • Hormones
  • Immunity
  • Insulin storage
  • Male fertility
  • Nucleic acid synthesis
  • Numerous enzymes
  • Prostaglandin function (see Fats in Part II)
  • Protein digesting enzymes
  • Protein synthesis
  • Superoxide dismutase (antioxidant enzyme)
  • Vitamin A metabolism and distribution

Good food sources

  • Eggs
  • Leafy green vegetables
  • Meat
  • Nuts
  • Seafood
  • Seeds
  • Whole grains

Deficiency symptoms

  • Abnormal hair loss
  • Acne
  • Anorexia
  • Depression
  • Impaired taste and smell
  • Infertility in men
  • Mental illness
  • Nervousness
  • Nystagmus
  • Poor growth in children
  • Poor hair growth
  • Sensitivity to light (photophobia)
  • Skin rashes
  • Slow wound healing
  • White spots on fingernails

Preventing deficiency

The times when zinc is in most demand include pregnancy, when breast-feeding, if suffering a wound, burn or infection, and as we grow. The zinc intake should be particularly high at these times, if necessary by adding a zinc supplement to the diet.

Doctors in the UK who regularly test patients for their mineral status find that mild zinc deficiency is extremely common, and often accounts for problems such as infertility in men, acne in teenagers, and low birthweights. Zinc is not added to artificial fertilizer, therefore if natural soil levels become depleted crops may contain very little zinc. In general zinc bioavailability is better from animal foods than from plant foods. Zinc absorption can be seriously reduced by the consumption of phytic acid (found in raw whole grains and bran), tea or coffee in the same meal.

Other causes of zinc deficiency include the contraceptive pill, and high-dosage iron and folic acid supplements prescribed by doctors for pregnant women. These can seriously lower zinc levels or inhibit zinc absorption (Am J Clin Nutr 1986;43:258-62). In contrast to iron, zinc is not stored and is easily lost from the body. Zinc deficiency may be common in pregnancy (Hambidge et al. Zinc nutritional status during pregnancy: a longitudinal study. Am J Clin Nutr 1983;37(3)429-42).

For babies, the bioavailability of zinc from human milk is better than that from cow’s milk formula. This is thought to be because of the high citric acid and picolinic acid content of human milk.

Information compiled by Linda Lazarides
Naturopathic Nutritionist, Author, Educator

Linda Lazarides is Course Director of the School of Modern Naturopathy and author of eight books on health, nutrition and naturopathy.

Facebook Twitter Google+ 

Comments

Comments are closed.