Did you know that Australians spend over $100 million a year on vitamin D supplements and we have the highest rate of skin cancer globally? Yet 1 in 4 Aussies are vitamin D deficient!

In a first-of-its kind webinar, watch Dr Flávia Fayet-Moore and GP Dr Jill Gamberg as they explore a new way to improve vitamin D status and address this nutrient of concern for all Australians.

In this webinar, you’ll learn about:

  • Pros and cons of different strategies to improve vitamin D status
  • How to determine which clients are at risk
  • Lifestyle strategies to meet vitamin D needs
  • New research on mushrooms and the connection to vitamin D
  • At the end of the webinar, you’ll understand why when it comes to vitamin D, two sources are best.

Dr Flávia Fayet-Moore’s Section 

Dr Jill Gambert’s Section

If you have any questions about the content of this webinar please email info@nraus.com

Questions and Answers from Webinar Attendees 

How many mushrooms should we recommend our patients consume daily?

Currently there are no specific recommendations for daily mushroom intake. However, most adults should aim for at least 5 serves of vegetables a day. A serve of vegetables is approximately 75g and could be made up of ½ cup of cooked mushrooms or 1 cup of raw mushrooms. Exposing mushrooms to UV light from the sun will also help contribute to your vitamin D requirements, making mushrooms a great choice.


What is the best way to cook or consume mushrooms to increase the uptake of vitamin D?

Cooking does not appear to affect a person’s vitamin D uptake from mushrooms.  Research examining raw, cooked and powdered mushrooms have all reported increases in 25-hydroxyvitamin D in the blood after consumption. However, cooking method can impact the amount of vitamin D initially contained within a mushroom. Mushrooms will lose some vitamin D in the cooking process and higher heat will lead to a larger loss of vitamin D. To retain the maximum amount of vitamin D, use shorter cooking times at a lower heat or add some lemon juice to your meal.

What do we know about the impact of cooking on vitamin D?
Do mushrooms retain vitamin D in any particular form?

Mushrooms will lose some vitamin D in the cooking process, as higher heat levels lead to larger losses of vitamin D. However, as they also lose some water weight during cooking, 100g of cooked mushrooms will still have greater vitamin D compared to 100g of raw mushrooms. To retain the maximum amount of vitamin D use shorter cooking times at a lower heat or add some lemon juice to your meal.

Is the recommendation of 15% of the body exposed to sun refer to arms only OR arms and legs?

This recommendation assumes that the face, arms and hands will be exposed to the sun, without sunscreen, to meet normal vitamin D requirements. In summer, sun exposure should only occur in the morning or afternoon. Whereas in winter, sun exposure should be at midday for optimum Vitamin D benefit.

Does clarified butter have vitamin D?

Clarified butter does contain vitamin D. It contains 1.2µg/100g vitamin D, compared with just 0.4µg/100g in plain salted butter  .

Can you explain ‘vitamin D equivalents’ listed in nutrient composition databases?

The specific type of vitamin D within foods can differ. Some foods contain 25-hydroxy-ergocalciferol (25(OH)D2), while others, contain 25-hydroxycholecalciferol (25(OH)D3), which have higher biological activity than their precursors. Mushrooms naturally contain ergosterol which is a precursor to vitamin D. When exposed to ultra-violet (UV) light e.g. sunlight or fluorescent light, ergosterol is converted to ergocalciferol (vitamin D2). ‘Vitamin D equivalents’ refer to the total of [vitamin D2 + vitamin D3 + 5*25(OH)D2 + 5*25(OH)D3] in a food.

How much nutritional yeast is required daily in order to significantly increase vitamin D level?

A 5g serve of vitamin-D enhanced nutritional yeast will provide 5µg of vitamin D. This is enough to meet he adequate intake for people aged up to 50 years of age.

Can you replace the vitamin C in lemon juice with lycopene in tomato paste?

Research linking lemon juice to vitamin D nutrient retention has not been replicated using lycopene in tomato paste.  Further, it is unknown which component of the lemon juice assists with vitamin D retention. Therefore, there is currently no evidence to support a replacement with lycopene in tomato paste.  Even without the addition of lemon juice, research reported that 60-80% of vitamin D was retained. If you enjoy mushrooms cooked with tomatoes you are still likely receiving a significant amount of vitamin D. Shorter cooking times and lower cooking temperatures were other factors that can assist to retain greater levels of vitamin D in mushrooms.

What is the best type of mushroom to maximise vitamin D intake? How does Button mushrooms compare to Shitake or Portobello mushrooms?

All edible mushrooms can make vitamin D when exposed to the sun. Therefore, the best mushroom to use is the one you enjoy eating. Button mushrooms and Portobello mushrooms contain more ergosterol (which is used to make vitamin D) compared to Shitake mushrooms. However, Shitake mushrooms are better at converting their ergosterol into vitamin D. The most important factor to consider is the mushrooms surface area. The greater the surface area exposed to the sun, the higher the levels of vitamin D.

What is better – raw vs cooked?

Cooking can help break down ‘anti-nutrients’ in foods (such as phytates and oxalates), which can help make minerals and some vitamins in mushrooms more available for absorption. Cooking can also help increase the absorption of antioxidants present in food. However, some vitamins, particularly water-soluble vitamins such as vitamin C and the B-group vitamins, can be destroyed during the cooking process. To get the most out of your mushrooms, enjoy a mixture of raw and cooked mushrooms in a variety of different dishes each day.

Does hypothyroidism increase the requirement of vitamin D?

People with hypothyroidism have a higher risk of Vitamin D deficiency. However, there is limited research to confirm whether their individual vitamin D requirements are higher than those without hypothyroidism.

What effect does sunscreen have on vitamin D production in the skin?

Broad-spectrum sunscreens prevent sunburn by stopping the UVA and UVB radiation from reaching the skin. UVB is required for the conversion of 7-dehydrocholesterol to cholecalciferol. Therefore, sunscreen use would prevent the synthesis of vitamin D to some extent. It is nearly impossible to cover every piece of skin that is sun-exposed, so it is likely that even with sunscreen, the skin will still be able to make some vitamin D. Interestingly, recent research by Dr Fayet-Moore found that people who report using sunscreen were actually at lower risk of Vitamin D deficiency, most likely because they also spent more time outdoors. During summer only 5-7 minutes of bare skin exposure in the morning or afternoon is required to meet vitamin D requirements for most adults. Sun safe guidelines should always be followed in the hottest part of the day.

I have Muslim friends and they are modest dressers, so is it worth asking patients about their style of dress and/or religion to help assess risk of vitamin D deficiency?

Use of religious coverings is one factor which should be assessed when deciding whether someone should be screened for vitamin D deficiency. Other factors include full time office workers, people with dark or extremely fair skin, people who are institutionalised or hospitalised for long periods of time, or people who don’t regularly consume vitamin-D containing foods, including oily fish, eggs, or mushrooms.