Why do you need it?
You need zinc for many crucial functions in the body. It is needed for healthy growth and development during pregnancy, infancy, childhood and adolescence as it helps build new cells and repair damaged tissue. It helps with wound healing, can strengthen your immune system and make you better able to fight infection. Zinc is also crucial to healthy vision and for male reproductive health as it increases sperm count and sperm motility.
Phytates
Pulses, grains and seeds contain zinc, but how well your body can absorb it from these foods may be reduced because they also contain phytates. You can limit this effect by soaking and sprouting pulses, grains and seeds. Although zinc may be absorbed at a lower rate from whole foods (due to the phytates), the higher amount of zinc in them more than compensates for the lower absorption, so you are better off sticking with whole foods.
Taking high doses of zinc reduces the amount of copper the body can absorb, which can lead to anaemia and weakening of the bones. You shouldn’t take more than 25 milligrams of zinc a day in supplements.
Deficiency
Symptoms of deficiency include skin problems (eg acne, eczema and rashes) hair thinning, weak immune system, slow wound healing, tiredness, diarrhoea, loss of appetite, mental slowness and impaired vision.
How much do you need?
The World Health Organisation (WHO) recommends 4.9 milligrams (mg) of zinc a day for women aged 19 to 65 and 7.0 milligrams (mg) of zine a day for men aged 19 to 65. The recommended intakes for infants, children, adolescents, older adults, pregnant and lactating women are given below.
Recommended nutrient intakes for zinc. Click to read more…
| Age group | Recommended nutrient intake mg/day | ||
|---|---|---|---|
| High bioavailability | Low bioavailability | ||
| Infants and children | |||
| 0-6 months | 1.1* | 2.8* | 6.6** |
| 7-12 months | 0.8* 2.5 | 4.1 | 8.4 |
| 1-3 years | 2.4 | 4.1 | 8.3 |
| 4-6 years | 2.9 | 4.8 | 9.6 |
| 7-9 years | 3.3 | 5.6 | 11.2 |
| Adolescents | |||
| Females, 10-18 years | 4.3 | 7.2 | 14.4 |
| Males, 10-18 years | 5.1 | 8.6 | 17.1 |
| Adults | |||
| Females, 19-65+ | 3.0 | 4.9 | 9.8 |
| Males, 19-65+ | 4.2 | 7.0 | 14.0 |
| Pregnant women | |||
| 1st trimester | 3.4 | 5.5 | 11.0 |
| 2nd trimester | 4.2 | 7.0 | 14.0 |
| 3rd trimester | 6.0 | 10.0 | 20.0 |
| Lactating women | |||
| 0-3 months | 5.8 | 9.5 | 19.0 |
| 3-6 months | 5.3 | 8.8 | 17.5 |
| 6-12 months | 4.3 | 7.2 | 14.4 |
Source: WHO, FAO. 2004. Vitamin and mineral requirements in human nutrition. 2nd ed. Geneva: WHO.
Where to find zinc
The best plant-based sources of zinc include pulses, nuts and seeds, wholegrain foods, leafy green vegetables and potatoes. The amount of zinc in plants varies based on levels in soil, so variety is key. The best way to ensure you get enough zinc is to eat a wide range of foods. To further increase zinc absorption, you can reduce the phytate content of pulses and grains by soaking, boiling or sprouting them.
- Pulses: Peas, beans, lentils and chickpeas are excellent sources of zinc. They are commonly consumed in Uganda and if eaten regularly, can provide a significant amount of zinc in the diet. One cup (196 grams) of cooked split peas contains nearly two milligrams of zinc while one cup (198 grams) of cooked lentils or (164 grams) of chickpeas contains 2.5 milligrams.
- Nuts and seeds: Pumpkin, sunflower and sesame (simsim) seeds, peanuts and cashew nuts, for example, all provide zinc. These can be consumed as snacks or added to meals for an extra boost. A small handful (28 grams) of pumpkin seeds contains 2.2 milligrams of zinc while a small handful of sunflower seeds contains 1.6 milligrams and a small handful of cashews, 1.4 milligrams. One tablespoon (nine grams) of sesame seeds contains 0.7 milligrams.
- Wholegrains: Millet and brown rice contain reasonable amounts of zinc. One cup (174 grams) of millet contains 1.6 milligrams of zinc and one cup (202 grams) of cooked brown rice contains 1.4 milligrams.
- Leafy green vegetables: Some leafy greens, such as spinach and kale, contain small amounts of zinc that can contribute to your overall intake if eaten regulalry. A cup (118 grams) of cooked kale, for example, contains just 0.3 milligrams of zinc.
- Potatoes: Both potatoes and sweet potatoes contain small amounts of zinc. While not as rich in zinc as other foods, they can still contribute to your overall zinc intake. A medium potato (180 grams) contains 0.5 milligrams of zinc.