Nutrition calculator: Check if your diet's missing key nutrients

If you think you might be eating too little or too much of a particular nutrient, use the nutrition calculator below to find out how much of it you actually need, based on your age and sex.

The calculator will also tell you which foods are high in the nutrient, whether you need to consume it every day and what to consider if you're contemplating taking supplements.

In the UK many of us struggle to eat enough fibre and vitamin D.

But with other nutrients, certain groups are more at risk than others of missing out.

For example, females aged 11-49 are more likely to be eating too little iron than other groups, and low calcium intake is a risk for girls aged 11-18, external.

There are more subtle differences between age groups when it comes to consumption of other nutrients. So if you have any concerns, check your risk with the calculator.

Sarah Stanner, science director at the British Nutrition Foundation explains: "Our diet helps support the immune system to cope with infections, and so anything we can do to try and eat well can help us get all the nutrients our body needs."

"While vitamin C and zinc supplements may fly off the shelves, it's important to remember the other key players in the immune system," says Stanner.

Other nutrients important for healthy immune function include vitamin D, and as we mostly get this from sunlight, the NHS says, external everyone over the age of four should consider taking a vitamin D supplement during autumn and winter.

Other nutrients linked to a healthy immune system include iron, vitamin A, vitamin B6, B9 (folate), B12.

If you are contemplating taking supplements, Stanner warns, "It's best to try to get as many nutrients as possible through food sources, as a healthy diet can provide a range of natural compounds that you will not find in supplements."

She adds there's no evidence supplements can prevent or treat viral infections, but advises that if you're worried your diet will not provide you with all the nutrients you need, you could consider a multivitamin and mineral supplement.

Disclaimer: Some nutrients are not included in the calculator because data isn't available.

Originally published April 2021, updated March 2026.

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