Facts
	Zinc (Zn) is an essential trace mineral occurring between 1.5-2.g grams of Zn making it almost as abundant as iron.
	Zn has only been recognised since 1974 by the National Academies' of Science.
	The typical intake of Zn in Western diets hovers around 10 mg, one-third less than the recommended dietary intake.1

Functions
	Zn has a variety of functions in the body. Nearly every enzyme reaction in the brain involves zinc.1 It is a component of at least 25 enzymes involved in digestion and metabolism, including carbohydrate digestion and phosphorous metabolism.1,2.
	Zn is essential for general growth and proper development of the reproductive organs and prostate gland function.2,3
	It also may help prevent acne and control the activity of oil glands.3 It also aids in the synthesis of protein and collagen formation, promotes a healthy immune system, aids in wound healing and allows for enhanced vision, taste and smell.1-3
	Zn is also a component of insulin and many vital enzymes.2,3 It also will fight and prevent against the formation of free radicals. Zinc also increases the absorption of vitamin A.3

Requirements
The Recommended Daily Allowance for Zinc is 15mg.


Signs of Deficiency
Symptoms include: retarded growth, delayed sexual maturity, prolonged healing of wounds, diminished taste or smell, brittle and thin nails, acne, fatigue, hair loss, high cholesterol levels, poor nigh vision, impotence, increased susceptibility to infection, infertility, poor memory, propensity for diabetes, prostate problems, poor appetite, recurrent colds and flu and skin lesions.2-5


Note
Several factors increase the need for Zn including alcohol consumption, physical and mental stress, fatigue, susceptibility to infection and injury.2


Signs of Toxicity
Excessive intakes of zinc can interfere with copper and iron metabolism. Symptoms of toxicity include: gastrointestinal upset, dizziness, nausea, impaired immunity and adverse changes in HDL/LDL cholesterol levels.1,3 According to Prescription for Nutritional Healing, an individual should not consume more than 100 mg of zinc per day. Doses under 100 mg enhance immune function while dosages of 100 mg or more have the opposite effect.3


Current Research

Blood Sugar
A zinc deficiency directly affects the way the body handles glucose, according to the results of an animal study published in Pediatrics Annals. Examinations of rat livers show that when a zinc deficiency exists, a zinc-dependent enzyme (a branch point enzyme) that acts as a railroad-type switch determining the reaction between energy burning and fat storage, becomes inactive. "The result is that glucose is shunted toward making triglycerides [blood fats] that can be stored in the fatty tissues rather than being burned for energy." 6

Immune Function
The thymus, a gland located in the chest, distributes and nourishes T- lymphocytes, or white blood cells, that are the body's first defense against invading bacteria, virus or cancer cells.6 The thymus is full of zinc, which is necessary for cell division and protein synthesis. The thymus also secretes FTS, a zinc-dependent hormone important for immunity. Researchers have found that even marginal deficiencies of zinc impair FTS activity. Elderly individuals and persons with Down's Syndrome lack both FTS and zinc. When Down's Syndrome children were administered 1 mg of Zn per kg of body weight, the children suffered less infections and missed fewer days of school.6


Fertility
Sperm contains significant amounts of zinc.1 One researcher found that 10 to 15 % of patients tested at an infertility clinic had very low levels of zinc. 6

Obesity
Platon Collip, M.D., former professor of pediatrics at State University of New York, Stony Brook has found that children deficient in zinc might not be able to discern the difference between feeling hungry versus feeling full. Zinc-deficient children do not appear to rely on internal cues to stop eating. "I think a zinc deficiency may also affect some part of the brain involved in the self-monitoring of the body, a kind of satiation center that lets you know when you've had enough to eat or drink."6


Osteoporosis
Zinc-dependent hormones are also involved in bone metabolism. Currently researchers postulate that zinc may help weak bones attract calcium . Researchers in Turkey demonstrated that persons with osteoporosis had 25 % lower levels of zinc than those without osteoporosis.6