Dietary Zinc
In the body
An adult body contains about 1.5 g of zinc in women and 2.5 g in men, most of it in muscle and bone. Zinc also supports growth in pregnancy, infancy, childhood and adolescence and is involved in the sense of taste.[1]
The body regulates its zinc through absorption from food and excretion into the gut: the more zinc a person eats, the more they absorb, but the smaller the share.[1]
Food and supplements
Meat, fish and other seafood, eggs and dairy products are good sources, and oysters are particularly rich. Beans, nuts and whole grains contain zinc too, but the body absorbs less of it from these plant foods.[1]
Supplements commonly use zinc sulfate, zinc acetate or zinc gluconate. Taking a supplement with a lot of iron (25 mg or more) at the same time lowers the absorption of zinc.[1]
How much
In the United States, recommended daily amounts are 8 to 12 mg for adults and 2 to 13 mg for infants, children and adolescents, depending on age, sex and life stage. The tolerable upper intake level is 40 mg a day for adults and 4 to 34 mg for children, depending on age.[1]
Most people in the United States get enough zinc; deficiency is much more common in low- and middle-income countries.[1]
Who may get too little
- people with digestive disorders or after weight-loss (bariatric) surgery
- vegetarians and vegans
- pregnant and breastfeeding women
- infants who are still only breastfed after 6 months
- children with sickle cell disease and people with alcohol use disorder[1]
A lack of zinc can delay growth and cause diarrhoea and hair loss in children, affect thinking and mood in older adults, and raise the risk of complications in pregnancy.[1]
What zinc supplements do and do not do
- Colds: trials have had mixed results; in general, zinc lozenges or syrup taken early in a cold shortened it but did not appear to make it milder.
- Childhood diarrhoea: in low-income countries short courses of zinc shorten acute diarrhoea in children; the effect may be small in well-nourished children.
- Pneumonia in children: zinc can lower how often it occurs where deficiency is common, but used in treatment it does not significantly shorten recovery or lower the risk of death.
- Age-related macular degeneration: supplements with zinc, copper and antioxidants slow its progression in people at high risk of the advanced form.
- Type 2 diabetes: there is not enough evidence that zinc helps prevent or treat it.
Too much zinc
Too much zinc causes nausea, dizziness, headache, stomach upset, vomiting and loss of appetite. Taking 50 mg or more a day for weeks can block copper absorption, weaken immune function and lower high-density lipoprotein (HDL, "good") cholesterol; food alone rarely provides this much.[1]
Cold lozenges, nasal sprays, some homeopathic products and denture creams also contain zinc; overusing them can lead to zinc poisoning.[1]
Zinc can interact with some antibiotics (quinolones and tetracyclines) and with penicillamine, and some diuretics increase the loss of zinc in urine; people on medication should ask a pharmacist before starting a zinc supplement.[1]
Products containing it
- All Day Fit A-Z Compact tablets (S 06)