VRN and THL: A versatile and healthy diet is more essential in the prevention of coronavirus than individual food supplements

Publication date 3 Feb 2021

Porridge and berries

The significance of vitamin D in the prevention and treatment of COVID-19 has been studied a great deal over the past year, and the role of vitamin D has been discussed in the media. 

In their position paper, the National Nutrition Council and the Finnish Institute for Health and Welfare (THL) emphasise that numerous nutrients, not only vitamin D, are important for ensuring the functioning of the body’s defence mechanisms. No single nutrient can compensate the benefits of a good nutritional status and a versatile diet. 

The National Nutrition Council and the Finnish Institute for Health and Welfare recommend that those responsible for nutritional communication and experts working with clients in health care take in particular the importance of overall nutrition during the corona pandemic into account and provide guidance to all clients on the recommended use of vitamin D supplements. 

"There is no reliable research-based evidence on the benefits of higher than recommended doses of vitamin D supplements," says Suvi Virtanen, Research Professor at the Finnish Institute for Health and Welfare. 

“In a clinical context, vitamin D may be a part of pharmacotherapy, in which case the dose used is based on a medical assessment,” says Docent Leo Niskanen, who is head of his unit and the chair of the National Nutrition Council’s Monitoring Group on Supplementing Nutrition.

Diet as a whole decisive in ensuring good nutrition

A good nutritional status is essential for the functioning of the immune system and recovery from diseases. Cardiovascular diseases, diabetes, obesity and high age have proven to be risk factors for the severe form of coronavirus disease. With the exception of age, all these risk factors can be influenced with a health-promoting diet that meets dietary recommendations. 

An adequate and versatile diet contains a large amount of vegetables, fruit and berries, fibre-rich grain products and sufficient amounts of soft fats (oils, soft fat spreads, fish, nuts and seeds). The excessive consumption of hard fats, salt and sugary products should be avoided. A good diet is best achieved by eating regularly and ensuring proper meals on a daily basis. 

"A diet in compliance with recommendations can ensure sufficient intake of essential nutrients, strengthen the immune system and improve the body's fat and sugar values," Arja Lyytikäinen, Secretary-General of the Finnish Food Safety Authority describes the compilation and benefits of a versatile diet.

When should vitamin D supplements be used?

To ensure the adequate intake of vitamin D, a person’s diet should include daily consumption of vitamin D-fortified milk, dairy products or plant-based beverages and fat spreads as well as fish 2-3 times a week. If, for some reason, this recommendation is not realised, it is advisable to take 10 micrograms of a vitamin D supplement each day during the darkest time of the year from the beginning of October until the end of March. 

There are also more detailed recommendations for different population groups on the use of vitamin D supplements to ensure the adequate intake of vitamin D:

  • Women who are pregnant or breastfeeding: 10 micrograms/day year-round. 
  • Children under 1 year of age: 2-10 micrograms/day year-round (dose is case-specific depending on whether an infant is breastfed or the amount of formula/follow-on formula/vitamin D-fortified porridge or gruel they are fed)
  • 1-year-olds: 10 micrograms/day year-round. 
  • Children aged 2 to 17 years: 7.5 micrograms/day year-round.
  • Adults aged 18 to 74 years: 10 micrograms/day from the beginning of October to the end of March, unless a person uses vitamin D-fortified milk products or fat spreads on a daily basis and/or eats fish 2-3 times a week
  • Adults aged 75 and above 20 micrograms/day year-round (and 10 micrograms/day if a person consumes an abundance of vitamin D-fortified foods)
  • People who are outdoors very little, tend to dress in a manner that covers most of their body and who have dark skin: 20 micrograms/day year-round.


Improving one’s overall diet more important during corona pandemic than taking individual nutritional supplements. National Nutrition Council position paper 3.2.2021.

More information:

Suvi Virtanen
Research Professor, THL
National Nutrition Council member
tel. +358 29 524 8729
[email protected]

Arja Lyytikäinen
National Nutrition Council (VRN)
Tel. +358 50 409 9860
[email protected]

Leo Niskanen
Head of unit, PHHYKY,
Chairperson for the National Nutrition Council’s Monitoring Group for Supplementing Nutrition
Tel. +358 50 067 5727 
[email protected]
[email protected]

Vitamin D - recommendations for intake and use of supplements

Vitamin D supplement recommendations for babies (in seven languages)

Information bulletin for reception centres on vitamin D supplements, December 2019 (in Finnish) (PDF 97 KB)

Nutrition and the coronavirus epidemic (in Finnish)

Nutrition and food recommendations

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