Updated: Sep 20, 2021
Did you know that vitamin D is a hormone? When the rays of the sun hit your skin, vitamin D is produced as a response to the sunlight. We also get vitamin D from the food we eat, but only about 10% is taken up in our bodies this way.
We’ve all heard that a vitamin D deficiency causes rickets in children and osteomalacia – softening of the bones – in adults. Too low levels of the vitamin means we’re unable to maintain enough calcium in our blood for healthy bone growth. (1)
But emerging research suggests that a lack of vitamin D is also linked to a weaker immune system, fatigue, bone and back pain, and depression. (2)
In fact, one the most important functions of vitamin D is to help us fight viruses and bacteria. According to this research paper, it works directly with the cells that are responsible for combating infection. (3)
A number of observational studies point to a connection between a vitamin D deficiency and respiratory tract infections, such as colds and pneumonia. (4, 5)
It also looks like the good old D can help fight off Covid-19. Auckland-based pharmacist and metabolic researcher Dr Catherine Crofts has published research about the importance of keeping your vitamin D levels up – and keeping insulin levels down – to help with Covid-19.
“It’s not just going to help should we get Covid-19, it will actually help to boost the effectiveness of the vaccine,” says Dr Crofts. “Having adequate amounts of vitamin D also helps to mitigate the effects of flu and other respiratory viruses over winter.” (6)
How to get enough vitamin D and boost your immune system:
· Spend some time in the sun – but don’t get burnt!
I’m not arguing with the idea of protecting ourselves from UV radiation, but we have perhaps become too diligent with the sunscreen and covering up. Nearly a third (27%) of New Zealanders are below the recommended blood level of vitamin D, according to the Ministry of Health. (7) You can’t manufacture vitamin D if you’re wearing sunscreen, says Dr Crofts. Try to get outside during the day (especially in winter) and soak up some of that sun!
· Eat some fish and seafood, like salmon, tuna, mackerel, oysters, shrimp, sardines and anchovies
· Eat some mushrooms!
Interestingly, just like humans, mushrooms also produce vitamin D when exposed to UV light.
· Egg yolks are rich in vitamin D
Ulrika Hedquist Ballinger is a writer and an instructor at Vitality Lab.
She is currently training to become a Health Coach.
1. You and your hormones – Vitamin D, https://www.yourhormones.info/hormones/vitamin-d/
2. 8 Signs and Symptoms of Vitamin D Deficiency, Healthline, https://www.healthline.com/nutrition/vitamin-d-deficiency-symptoms
3 Martens et al, Vitamin D’s Effect on Immune Function, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7281985/
4 Kana Ram Jat, Vitamin D deficiency and lower respiratory tract infections in children: a systematic review and meta-analysis of observational studies, https://pubmed.ncbi.nlm.nih.gov/27178217/
5 Pletz et al, Vitamin D deficiency in community-acquired pneumonia: low levels of 1,25(OH)2 D are associated with disease severity, https://pubmed.ncbi.nlm.nih.gov/24766747/
6 Dr Catherine Crofts, Vitamin D helps fight Covid-19, says research, https://prekure.com/vitamin-d-fights-off-covid-19-says-new-research/
7 The Ministry of Health, https://www.health.govt.nz/your-health/healthy-living/food-activity-and-sleep/healthy-eating/vitamin-d