Dr Catherine Crofts has co-authored a paper about the importance of getting your insulin levels down and keeping your vitamin D levels up to help with Covid-19.

More than a quarter of New Zealanders have inadequate amounts of vitamin D throughout the winter period. I want to strongly recommend that people consider taking a vitamin D supplement or making sure they’re eating an adequate amount of foods that are rich in vitamin D over the winter, especially if you’re carrying a bit too much weight, if you live on the South Island, or if you don’t get much sunlight at all during winter.


You can’t manufacture Vitamin D if you’re wearing sunscreen.



Frankly, during the winter, I don’t seem to get outside during the middle of the day, but you need to have sunlight on adequate amounts of skin in the middle of the day to get manufactured vitamin D. If you’re on the South Island, 1 – shorter daylight, 2 – it’s cold, most people are muffled up, and 3 – we’ve all been told to wear sunscreen.


If you’re in the at-risk category, please take your vitamin D supplements.


You can’t manufacture vitamin D if you’re wearing sunscreen. So if you’re the at-risk category, please take your vitamin D supplements. It’s not just going to help should we get Covid-19, it will actually help to boost the effectiveness of the vaccine. It’s also believed to help with the flu vaccine and how well that takes within the body. Having adequate amounts of Vitamin D also helps to mitigate the effects of flu and other respiratory viruses over winter. If you want Vitamin D supplements to work really well, make sure you have it with some magnesium and selenium as well.

Dr Catherine Crofts is a Pharmacist, a metabolic health researcher at AUT and a PreKure Faculty member.


Learn more

Click here to read the research paper: Relationships between hyperinsulinaemia, magnesium, vitamin D, thrombosis and COVID-19: rationale for clinical management, Isabella Cooper et al, Open Heart, 2020