When was the last time you had your vitamin D levels checked? There is no better time than now as we see increasingly positive Covid-19 cases. This winter, we must take it upon ourselves to ensure that we protect ourselves adequately. There are easy at-home vitamin D tests to check your levels and a health practitioner like myself can guide you with respect to dosage and getting your vitamin D levels at optimal levels over the flu season and in this Covid-19 environment. It is important that you are empowered to take care of your own health and keep track of your levels.

The daily recommendation in the UK for vitamin D intake is 400IU daily but for many of us, these levels are insufficient for our wellbeing. The importance of vitamin D for our immune health has been highlighted particularly this year because there is compelling evidence that has shown that people with lower vitamin D status have poorer outcomes with respect to severity of Covid-19 symptoms. Underlying conditions such as diabetes and heart disease are associated with lower vitamin D levels. For people of colour, there is a prevalence of low vitamin D levels. This is why it is vital to get your vitamin D levels tested.

Vitamin D is in fact a key component of our immune system and not just for our bones or to prevent rickets. Although vitamin D regulates calcium and phosphorus absorption, it regulates our immune function, protecting against viral infections. In a recent study in Nutrients journal (May 2020), which compared vitamin D levels in patients testing positive with Covid-19 with those in patients who tested negative, significantly lower vitamin D levels were found in the Covid-19 patients.

How does vitamin D influence our immune system?

Our first line of defence when a pathogen invades our body is our innate immune system which works more effectively when vitamin D levels are optimal. Vitamin D also modulates our adaptive immune responses.

Vitamin D also has a role to play in influenza. A well-designed double-blind placebo study showed that administering therapeutic doses of vitamin D led to a significant decrease (42%) in the incidence of influenza infection.

How long will it take to get my vitamin D levels to a healthy level?

This depends on a number of factors including how low your vitamin D levels currently are and your magnesium status. Additionally, if you have a single nucleotide polymorphism ie a SNP in your vitamin D receptor (VDR) gene you will absorb vitamin D poorly. This can be tested using saliva-based DNA testing if you struggle to maintain a reasonable level despite supplementation. It is always best to have a vitamin D blood test before supplementing but you could also take a low maintenance dose if testing is not an option.

Vitamin D supplementation

If you are supplementing vitamin D, you should supplement with vitamin K2. Many supplement companies now provide Vitamin D with K2 . You should also consider that if you are low in magnesium (well over 50% of us are), you may find that it might take a bit longer to to get your vitamin D to an optimal level. This is because magnesium is required for adequate vitamin D absorption.

For instance, if your vitamin D level is at 25ng/ml (this is relatively low) and the goal is to optimise your levels to 50ng/ml, it will take approximately 3 months at a dosage of 4000IUs for about 50% of people to reach this level (this is for an individual who weighs 60kg). There is a Vitamin D calculator at Grass Root Health which will ask you to put in your current vitamin D level, your ideal level and your weight. It then calculates the daily dosage that you need in order to achieve that ideal level within the next 3 months. If in doubt, a nutritional therapist can advise.