                            VegSocUK Information Sheet
                              THE VEGETARIAN SOCIETY


   ___________________________________

                                      ZINC

   The mineral zinc is present in every part of the body and has a wide range of
   functions. It helps with the healing of wounds and is a vital component of
   many enzyme reactions. Zinc is vital for the healthy working of many of the
   body's systems. It is particularly important for healthy skin and is
   essential for a healthy immune system and resistance to infection.

  FUNCTIONS

   Zinc has a range of functions. It plays a crucial role in growth and cell
   division where it is required for protein and DNA synthesis, in insulin
   activity, in the metabolism of the ovaries and testes, and in liver function.
   As a component of many enzymes, zinc is involved in the metabolism of
   proteins, carbohydrates, lipids and energy.

   Our body contains about 2-3 g of zinc. There are no specific storage sites
   known for zinc and so a regular supply in the diet is required. Zinc is found
   in all parts of our body, 60% is found in muscle, 30% in bone and about 5% in
   our skin. Particularly high concentrations are in the prostate gland and
   semen. Men need more zinc than women because male semen contains 100 times
   more zinc than is found in the blood. The more sexually active a man the more
   zinc he will require. The recommended amounts of zinc for adult men are 1/3
   higher than those for women.

   The first signs of zinc deficiency are impairment of taste, a poor immune
   response and skin problems. Other symptoms of zinc deficiency can include
   hair loss, diarrhoea, fatigue, delayed wound healing, and decreased growth
   rate and mental development in infants. It is thought that zinc
   supplementation can help skin conditions such as acne and eczema, prostate
   problems, anorexia nervosa, alcoholics and those suffering from trauma or
   post-surgery. It is always better to seek theadvice of an expert before
   dosing yourself with supplements. If you choose to take a zinc  supplement you
   should not need more than the daily recommenced amount unless medical advice
   says otherwise.

  DIETARY SOURCES

   Zinc is present in a wide variety of foods, particularly in association with
   protein foods. A vegetarian diet often contains less zinc than a meat based
   diet and so it is important for vegetarians to eat plenty of foods that are
   rich in this vital mineral.

   Good sources for vegetarians include dairy products, beans and lentils,
   yeast, nuts, seeds and wholegrain cereals. Pumpkin seeds provide one of the
   most concentrated vegetarian food sources of zinc.

   Only 20% of the zinc present in the diet is actually absorbed by the body.
   Dietary fibre and phytic acid, found in bran, wholegrain cereals, pulses and
   nuts, inhibit zinc absorption. Phytic acid forms a highly insoluble complex
   with zinc which the body cannot absorb. Cooking processes can reduce the
   adverse effects of both phytic acid and dietary fibre on zinc absorption.
   Baking can destroy over half the phytic acid in wholemeal bread. Zinc
   deficiency occurs where a large part of the diet consists of unleavened
   bread, such as Iran and other Middle East countries. High levels of the toxic
   mineral cadmium can also prevent zinc absorption because these two minerals
   compete for absorption. Conversely high levels of zinc in the diet can
   prevent the absorption of cadmium. Various chemicals added to many processed
   foods can also reduce zinc absorption eg phosphates, EDTA. A deficiency of
   zinc in the diet means zinc absorption is improved.

   Zinc is lost via the faeces, urine, hair, skin, sweat, semen and also
   menstruation.

    Good sources of zinc (single servings).

Tahini paste (20g or 2/3 oz)            1.1 mg
Pumpkin seeds (20g or 2/3 oz)           1.3 mg
Cheddar cheese (30g or 1 oz)            1.2 mg
Dried yeast (10g or 1/3 oz)             0.8 mg
Wholemeal bread (40g or 1 1/2 oz)       0.8 mg
Chickpeas (200g or 2 oz)                2.8 mg
Baked beans (225 g or 8 oz)             1.6 mg
Muesli (60 g or 2 1/4 oz)               1.3 mg
1 Fruit yoghurt (150 g or 5 1/4 oz)      0.9 mg
1 Vegeburger (100g or 3 1/2 oz)          1.6 mg

    Fair sources

3 Brazil nuts (10 g or 1/3 oz)          0.4 mg
3 Dried figs (60 g or 2 oz)             0.5 mg
1 Orange (140 g or 5 oz)                0.3 mg
Peas, frozen/canned (80 g or 2 2/3 oz)  0.6 mg
Peanut butter (20 g or 2/3 oz)          0.6 mg
Potatoes, boiled (200 g or 7 oz)        0.4 mg
6 Almonds (10 g or 1/3 oz)              0.3 mg
    Poor sources

Butter (7 g or 1/4 oz)                  0.01 mg
Dried dates (15 g or 1/2 oz)            0.04 mg
Raisins & Sultanas (15 g or 1/2 oz)     0.01 mg


  REQUIRED INTAKES

   The old Recommended Daily Amounts (RDAs) have now been replaced by the term
   Reference Nutrient Intake (RNI). The RNI is the amount of nutrient which is
   enough for at least 97% of the population.

    Reference Nutrient Intakes for Zinc, mg/day.

Age                     RNI

0 to 6 months           4.0 mg
7 months to 3 yrs       5.0 mg
4 to 6 yrs              6.5 mg
7 to 10 yrs             7.0 mg
11 to 14 yrs            9.0 mg

Adult men               9.5 mg
Adult women             7.0 mg
Pregnant women          7.0 mg
Breast feeding women    9.5 to 13 mg

   Pregnant women do need extra zinc, but it is thought that demands are met by
   increased absorption from the gut. Breast feeding mothers need extra zinc in
   their diet. Breast milk contains over 2 mg of zinc in the first four months
   and women need an extra 6 mg a day to cover these demands. Breast feeding
   women must include a generous serving of at least one good source of zinc in
   their diet each day.

   The iron supplements routinely prescribed for pregnant women when there is no
   sign of anaemia may compromise zinc status. This is because the interactions
   between essential minerals are complex and too much of one may cause an
   imbalance of another.

   Excess zinc is toxic. Too much zinc will interfere with the metabolism of
   other minerals in the body, particularly iron and copper. Symptoms of zinc
   toxicity occur after ingestion of 2 g of or more and include nausea, vomiting
   and fever.

  MEAL PLAN

   Sample one day's meal plan to meet the RNI of 9.5 mg for an adult man.

Breakfast

Bowl of muesli with milk        1.32 mg
1 slice of toast                 0.8 mg

Lunch

Baked beans (225g or 8 oz)      1.57 mg
2 slices of toast                1.6 mg
Cheese (30 g or 1 oz)            1.2 mg
(or Pumpkin seeds, 20 g or 2/3 oz)

Evening meal

Potatoes, boiled (200g or 7 oz)  0.4 mg
Peas (80 g or 2 2/3 oz)         0.56 mg
1 Vegeburger (100g or 3 1/2 oz)  1.3 mg
1  Fruit yoghurt                0.94 mg

Total zinc intake               9.69 mg


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//
This article is copyright to the Vegetarian Society (UK), but may be freely
copied for non-commercial use provided it is kept intact, not altered
and these lines are included.

For futher information contact: The Vegetarian Society, Parkdale, Dunham Road,
Altrincham, Cheshire WA14 4QG, England. Tel: (England) 061 928 0793
email: vegsoc@vegsoc.demon.co.uk
//



[The text of this file was obtained from the Vegetarian Society (UK) in
March 1995.]

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