From Food to Function: The Complete Scoop on Zinc's Benefits and Risks

Healthy individuals can get their daily zinc requirements from non-vegetarian foods such as oysters, lobsters, chicken and pork.

It is harder to meet all your zinc requirements with a purely vegetarian diet but it is possible—you should soak, sprout, ferment or leaven these foods to increase the availability of the zinc present in them. The vegetarian sources of zinc include:

• Rajma or kidney beans
• Chickpeas or white chana
• Pumpkin seeds
• Tofu
• Cashew nuts
• Pine nuts or chilgoza
• Green peas
• Almonds
• Avocado
• Blackberries and blueberries 

Zinc supplements

Research is divided on whether you should take zinc supplements. For example, a study in which South Asian children were given zinc supplements showed improved health outcomes. However, another study on protein metabolism in middle-aged men showed that zinc supplements did not make a significant difference among the participants.

Your age and the desired outcome are just two of the many things you should consider before taking zinc supplements. Ideally, you should talk to your doctor before taking any supplements. In this case be sure to also ask about the dosage, as an excess of zinc can also produce some side-effects.

That said, zinc supplements are available in six main forms:

• Zinc gluconate
• Zinc acetate
• Zinc sulphate
• Zinc picolinate
• Zinc orotate
• Zinc citrate

They vary slightly in terms of taste and bioavailability of zinc. Zinc gluconate is most often used in nasal sprays and lozenges to treat the symptoms of a cold. Zinc sulphate oral solution is sometimes prescribed for the treatment of diarrhoea in children.

Researchers began looking into the importance of zinc for humans in the 1960s, in West Asia where they were able to link short stature (dwarfism) and smaller testicular development (hypogonadism) in adolescents with zinc deficiency.

Subsequently, researchers were able to reduce these symptoms through zinc supplementation in prepubescent boys in Egypt and Iran. Similar efforts in the US in the 1970s showed that zinc supplementation could improve growth metrics (length and weight) in boys up to six months of age.

Since then, scientists have uncovered the many uses of zinc for the body. For example, our immune cells use zinc as a messenger.

Today, according to an article published in 2013 in Advances in Nutrition—a peer-reviewed journal published by Oxford University Press—doctors use zinc in the “management of acute diarrhoea in children, Wilson's disease, the common cold and for the prevention of blindness in patients with an age-related dry type of macular degeneration and...decreasing the incidence of infection in the elderly. Zinc not only modulates cell-mediated immunity but is also an antioxidant and anti-inflammatory agent”.

Strengthens the immune system: Zinc helps the body fight infections and ensures the correct functioning of the immune system.

• Helpful in wound healing: Zinc plays an important role in the process of skin repair and wound healing.
• Useful in DNA and protein synthesis: Zinc is essential in DNA formation and protein production.
• Improves taste and smell: Zinc is essential for the correct identification of taste and smell.

We all know that we need minerals in our diet to stay healthy. But how much we need of each is less known. Well, minerals are divided into two categories:

• Macrominerals: We need more than 100 milligrams a day of calcium, magnesium, phosphorus, sodium, potassium, sulfur and chloride—these are known as macrominerals.
• Microminerals: We need smaller quantities of iron, zinc, manganese, copper, selenium, cobalt and fluoride on a day-to-day basis—these are known as microminerals or trace minerals.

The difference between macro and micro or trace minerals is mainly the quantities we need, not how important they are for our health. After all, we all know how important iron is for the body to avoid anaemia.

According to the National Institutes of Health Office of Dietary Supplements, US, the amount of zinc we need daily is: Daily requirements of zinc as per FSSAI:

• Children (1-3 years): 3 mg per day
• Children (4-8 years): 5 mg per day
• Teenagers (9-13 years): 8 mg per day
• Teenagers (14-18 years): 11 mg for boys and 9 mg for girls per day
• Adult men: 11 mg per day
• Adult women: 8 mg per day
• Pregnant women: 11-12 mg per day
• Breastfeeding women: 12-13 mg per day

Though rare, taking too much zinc can cause some side-effects such as:

• Indigestion, stomach pain and/or diarrhoea
• Nausea and vomiting
• Headache
• Copper deficiency, which may present as weakness or numbness in limbs
• Overuse of zinc-based nasal sprays has been linked with loss of sense of smell (anosmia)
• Researchers say the link between an excess of zinc and prostate cancer is unclear, but it is still a good idea to avoid taking too many zinc supplements.

Zinc is important for proper development, immune function, protein synthesis and a myriad other functions in the body. Though we need only trace amounts of this mineral, zinc deficiency is very common. It can lead to a host of problems like growth retardation, male hypogonadism, cognitive problems, alopecia and several skin problems.

Oysters and animal proteins are the best food sources of zinc. That said, vegetarians and vegans can also get adequate zinc through large amounts of rajma, pumpkin seeds, cashew nuts and tofu. It's important to remember that phytates (plant compounds) in many plant-based diets inhibit the absorption of zinc in the body. Try soaking, sprouting, fermenting, leavening any vegetarian sources of zinc, to increase the bioavailability of the mineral (the extent to which it can be absorbed in the body).