An Australian study, which systematically reviewed 68 studies, concluded mushrooms can be as effective as taking vitamin D supplements, along with other nutrition benefits.

But they need to be exposed to ultraviolet light in the sun, just for 15 minutes, so they can convert one of the compounds in mushrooms called ergosterol to ergocalciferol, which is vitamin D2.

It’s a different form of vitamin D to what we manufacture ourselves from sunlight, but it does the same thing. It’s a bio-available form of vitamin D, but it’s coming from a plant food!

If you take about 100g, between 5-7 button mushrooms, and put them on a plate out in sunshine, resting on their top to create the greatest exposure space, in about 15 minutes they will ‘manufacture’ vitamin D. If you eat them raw you get all the nutrients in the mushroom, but as Vitamin D isn’t destroyed by cooking, it’s fine to cook them your favourite way – like grilling a portobello mushroom drizzled with olive oil, then serving on a wholemeal bun – to get all the benefits.

Vitamin D is so important as it’s critical for our bone health, because it regulates and helps calcium be absorbed.


Mushrooms are rich in essential vitamins and minerals, such as Vitamin D, riboflavin and selenium. They contain a wide range of valuable antioxidants, and are a unique bundle of protein, carbohydrates and fibre, all in a tasty little package.

Plus they are low in fat, sodium and kilojoules; are naturally gluten free; help keep blood glucose levels normal and have a very low GI – so they are a delicious option for people with diabetes or following a gluten-free diet.

Adding mushrooms to your diet can help boost immunity, give your skin a healthy glow, keep your heart healthy and more!

Finally, mushrooms have a deliciously rich ‘umami’ flavour, which can replace some of the salt used in recipes.

Listen to my podcast discussing this topic with Dee Dee on radio 3AW, and watch my dietitian colleague Laura Ford’s tik tok video demonstrating how to boost vitamin D with mushrooms in the sun – it captured over 180,000 views worldwide over the research findings!