Zinc is present in all organs and tissues, and in body fluids, with the majority found in bone, liver, kidney, muscle and skin. Zinc is essential for over 300 enzymes involved in major metabolic pathways. It is required for the production of white blood cells for immune function. Some research shows that zinc is more effective at warding off colds than vitamin C.
Zinc is important in growth and development. It affects blood clotting, thyroid hormone function, behaviour and learning abilities, wound healing and is an important component of sperm. Zinc is also essential for producing retinal that is necessary for visual pigments. Zinc also is essential to taste, smell and mood.
Zinc absorption is affected by the other nutrients ingested, as well as pancreatic secretions into your gastrointestinal tract. Low intakes of zinc are absorbed more effectively than higher doses.
A person with depleted or low zinc status will absorb more zinc from foods than someone with sufficient zinc. Symptoms of zinc deficiency are growth retardation, male hypogonadism (reduced testosterone secretion), poor appetite, skin changes, delayed wound healing and an impaired sense of smell and taste (common in elderly). Zinc is necessary for healthy respiratory systems and a strong heart. It helps build a healthy immune system and to reduce inflammation. Zinc also helps with strong bones, increasing your bone mineral density.
For athletes, zinc is important for your body to produce optimal testosterone levels which help to build lean body mass (muscle). It’s also essential for repairing your muscles after exercise and for a well functioning metabolism, which is necessary for lean muscle mass.
Increasing absorption of Zinc
Enhancers of absorption include animal foods such as meat, which are believed to aid absorption due to the interaction between zinc and protein products.
Inhibitors of absorption include phytate from plant foods, principally cereals and legumes. Phytate, together with calcium, produces the greatest inhibitory affect. Oxalates (found in spinach, berries, chocolate and tea), polyphenols such as tannins (found in tea) and fibre all impair the absorption of zinc.
- The RDI for Men is 14mg/day
- The RDI for women is 8mg/day
Tips for increasing Zinc
- Eat foods rich in zinc rather than a supplement for optimum absorption and to prevent excess zinc levels interfering with availability of other nutrients
- Zinc is absorbed more readily from meat than from vegetables.
- Zinc is also present in legumes and cereals; however, phytates present in these foods can interfere with zinc availability.
- Cooking meat does not lead to dramatic loss of zinc. In plant foods, you can expect some zinc loss in cooking liquids, for example, boiled lentils lose about 10-20% of their zinc content. Steam where possible to reduce zinc loss.
- Soaking beans, seeds, and grains for several hours, then allowing sprouts to form, may significantly improve zinc bioavailability from these foods.
Foods high in Zinc
|Sesame Seeds||0.25 cup||206.3||2.79|
|Pumpkin Seeds||0.25 cup||180.3||2.52|
|Garbanzo Beans||1 cup||269||2.51|
|Green Peas||1 cup||115.7||1.64|
|Mushrooms, Shiitake||0.50 cup||40.6||0.96|
|Mushrooms, Crimini||1 cup||15.8||0.79|
|Beet Greens||1 cup||38.9||0.72|
|Summer Squash||1 cup||36||0.7|
|Swiss Chard||1 cup||35||0.58|
|Brussels Sprouts||1 cup||56.2||0.51|