Nutrients in Focus: Zinc

Zinc

I often get questions about specific nutrients and where we can get them from in food for ourselves and for our little ones. So I wanted to put together a short blog to help break it down. In this blog, we’ll take a closer look at zinc. What it is, why we need it and how we can get it.

What is zinc and why is it important?

Zinc is a mineral which is needed in small amounts for a wide variety of functions in the body. It’s needed for protein and carbohydrate metabolism, DNA synthesis, wound healing, immune function, cell replication and growth.

Babies & Children

For children, zinc is particularly important for growth and immune function. Deficiency has been linked to poor growth and decreased resistance to infections. Zinc deficiency is rare in the UK and ensuring a good intake from a wide variety of foods will help to make sure little ones get what they need. Up to 6 months of age, breastmilk will provide sufficient zinc for babies. But after this, additional intake from foods is necessary to meet requirements. For formula-fed babies, formula contains sufficient amounts. Zinc-rich foods should then be included when introducing solid foods to ensure adequate intake.

The amount of zinc in breast milk changes over the first few months. It is highest in the first two weeks, at 0.4mg per 100ml, reducing to 0.1mg per 100ml by six months. While in formula milk it is 0.5ml per 100ml. The higher content in formula milk is because zinc from breast milk is more bioavailable. So more is needed from formula milk to absorb the same amount.

Pregnancy

In pregnancy zinc is important both for maternal health and for the health of the growing baby. Changes in the absorption of zinc in the mother’s body mean that zinc requirements are not specifically increased during pregnancy. But this is dependent on sufficient intakes throughout the pregnancy.

When breastfeeding, zinc requirements are higher than for both non-pregnant and pregnant women. Increasing by 6mg per day for the first four months and by 2.5mg per day from 4 months onwards.

While extremely rare, it is possible to have too much zinc. Very high doses can cause symptoms including diarrhoea and vomiting and impair the metabolism of copper in the body. Taking high dose supplements of zinc is not recommended. For the majority of us, it’s possible to get enough from our diets and so a supplement is certainly not essential.

How much do we need?

How much zinc we need varies by age and gender. The below table shows the recommendations across the different stages.

Zinc

(Adapted from the British Nutrition Foundation)

Where do we get it from?

 Zinc Infographic

Zinc Infographic

Bioavailability of Zinc

Bioavailability refers to the amount of a nutrient which is absorbed by the body. Rather than just how much a certain food contains of that nutrient.

For zinc, certain plant substances called phytates can decrease how much zinc our bodies absorb from some foods. Phytates are found in many of the plant-based foods that contain zinc. Including grains, nuts, seeds and legumes. Therefore vegetarian and vegan diets can have a lower overall bioavailability for zinc.

It is still possible to get enough zinc from a plant-based diet, by including plenty of zinc-rich foods. While nutrient absorption can be affected, many of these foods have important beneficial effects on health and are a significant part of a varied and balanced diet.

There are also some ways to enhance the absorption of zinc. Including fermented foods (such as kefir, sauerkraut, miso, kimchi and sourdough) and soaking dried beans and pulses before cooking.

Generally eating a balanced diet, whether plant-based or a meat eater, is the best way to make sure you and your baby/child are getting enough in the way of nutrients every day, including zinc.

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