Zinc deficiency can happen in people who have problems absorbing nutrients, for example, older people and those who have some gut diseases. Some medicines can also increase the loss of zinc through urine.
Increased loss. Exercising, high alcohol intake, and diarrhea all increase loss of zinc from the body.
If you are taking zinc, the following foods should be avoided or taken 2 hours after you take zinc: Bran. Fiber-containing foods. Phosphorus-containing foods such as milk or poultry.
People who drink excessive alcohol can also not absorb zinc normally. Long-term illnesses, such as chronic liver or kidney disease can also result in low absorption of zinc. High-dose iron supplements can also affect the way zinc is absorbed, leading to deficiency.
Zinc is best absorbed when taken with a meal that contains protein. The best sources of zinc are oysters (richest source), red meats, poultry, cheese (ricotta, Swiss, gouda), shrimp, crab, and other shellfish.
As mentioned, zinc is an essential cofactor to have the desired functions of vitamin D. Similarly, vitamin D can also influence zinc absorption and homeostasis by regulating its transporters.
Caffeine may reduce the absorption of manganese, zinc and copper. It also increases the excretion of the minerals magnesium, potassium, sodium and phosphate.
Zinc Concerns
Phytates, an antioxidant in coffee, may inhibit absorption of zinc. Coffee has been found to affect the bio-availability of zinc, in lab tests, by up to 21 percent or 32 percent. The recommended daily intakes of zinc for men is 11 milligrams each day and 8 milligrams for women.
Magnesium assists your body in regulating zinc levels, but high intakes of zinc can be detrimental to magnesium absorption – only abnormally high doses (around 142 mg of zinc per day) will reduce magnesium absorption.
Exhaustive exercise, and the sweating that accompanies it, can deplete zinc stores as reported in a study of professional athletes. Supplementing with zinc for four weeks had positive effects on plasma zinc, testosterone production and thyroid hormone status.
Consume lots of sugar or high fructose corn syrup and you will risk depleting zinc as well as vitamin C, calcium, chromium, copper, and magnesium.
Negative zinc balances in study A and positive zinc balances in study B were observed in both tea and no tea dietary treatments. Tea consumption showed a small but not statistically significant adverse affect on zinc bioavailability in humans.
Pecoud et al. [60] administered 50 mg of zinc (as 220 mg ZnSO4 in gelatin capsules) to 18 subjects orally with breakfast and found that the consumption of 200 mL of milk and 50 g of cheese with breakfast (100 mL coffee, 50 g jam, 10 g butter and 100 g brown bread or 10 g white bread) reduced zinc absorption.
Evidence has shown that green tea both suppresses and has no effect on zinc absorption.
It was concluded that the higher level of zinc supplementation had a negative effect on vitamin B12 in lambs. Higher inclusion level of dietary zinc could inhibit vitamin B12 synthesis in the rumen of lambs.
Lectins in legumes (beans, peanuts, soybeans), whole grains—can interfere with the absorption of calcium, iron, phosphorus, and zinc.
As research from Oregon State University's Linus Pauling Institute points out, the zinc in foods like oysters, red meat and eggs is more bioavailable, meaning that your body can more readily absorb and use it. This is because animal proteins improve zinc absorption.
Do not take zinc supplements and copper, iron, or phosphorus supplements at the same time. It is best to space doses of these products 2 hours apart, to get the full benefit from each dietary supplement.
There are no negative vitamin interactions when taking vitamin C. Just like zinc, you can take other vitamins with vitamin C. In fact, vitamin C promotes iron absorption from foods, which means it is actually beneficial to take to get the proper nutrients from other food.
The results suggest that ascorbic acid does not affect the absorption of normal dietary levels of zinc and calcium.
The largest body of evidence demonstrates stress-induced depletion of magnesium and zinc, although several studies (both human and animal) demonstrate the effects of stress on calcium and iron concentrations.
The best source of zinc is oysters, but it's also plentiful in red meat and poultry. Other good sources are beans, nuts, crab, lobster, whole grains, breakfast cereals, and dairy products.
In contrast with its effects on iron status, green tea decoction significantly increased the serum zinc in the tea 100 group by 24% (p < 0.001). It also increased the blood precipitate of zinc by 50 (p < 0.01) and 75% (p < 0.0001) in tea 50 and tea 100 groups, respectively.
It often takes 12 weeks before any improvement is seen. Long-term zinc supplementation requires 1–2 mg of copper per day to prevent copper deficiency.