Some of the best food sources of zinc include spinach, lamb, beef, scallops and mushrooms. Healthy adults need around 10 mg of zinc per day; children and teens need less and the amount varies according to age and gender. Zinc deficiency is relatively common worldwide, but is not common in Canada. People who may have a greater than average requirement for zinc include those with chronic or recurring infections, skin conditions, ADHD or alcoholism.
Taking high doses of supplemental zinc daily for long periods of time has been implicated in doubling the risk of prostate cancer. Doses of 10-30 grams of zinc can be fatal. People with HIV/AIDS should avoid zinc supplements unless taken under medical supervision.
If you are on any of the following medications, do not take zinc unless you have been advised to do so by your health care practitioner:
- Amiloride (Midamor)
- Antibiotics (Quinolone antibiotics such as ciprofloxacin (Cipro), levofloxacin (Levaquin), ofloxacin (Floxin), moxifloxacin (Avelox), gatifloxacin (Tequin) enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar))
- Antibiotics (Tetracycline antibiotics such as demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin, Sumycin))
- Cisplatin (Platinol-AQ)
Also note that taking zinc sulfate with black coffee instead of water reduces zinc absorption by half and that eating fiber at the time the zinc supplement is taken can reduce its absorption.