With a Covid-19 vaccine on the immediate horizon does this mean that attention might be focussed away from concern about the high levels of deficiency that compromise the health and increased susceptibility to the virus?
Hopefully not, as despite a Covid-19 vaccine we still need to ensure we are all consuming and fuelling our bodes, with the right amount of Vitamin D throughout all seasons. Here are the essential reasons as to why we need Vitamin D whether there is a Covid-19 vaccine or not:
- The role of vitamin D in supporting both innate and adaptive immunity is well recognised, so supplementation for these benefits is a given.
- A wider perspective on the immune benefits of vitamin D identifies, surprisingly, there has been little research examining the effect that supplementation has on enhancing the response to vaccines for similar respiratory conditions such as influenza and that might be suggestive of a benefit to enhance the efficacy of the new Covid-19 vaccine.
- In the case of influenza vaccines, it appears that benefits of supplementation may be “strain” specific, with dosing prior to vaccination of certain subtype viruses delivering a higher level of immunogenic response than for others.
Until the Covid-19 vaccine becomes available and this effect has been evaluated it will be impossible to predict whether this observation will be repeated in the case of this vaccine, and it unlikely at this early stage that vitamin D status will have been investigated as a possible “confounder” in terms of enhancing the response in current immunisation trials.
The ongoing use of vitamin D which helps support immunity is an essential common-sense strategy. And given that the duration or absolute level of immune protection provided by the vaccine has not been clearly defined, again maintenance of a vitamin D status that delivers a positive contribution to immunity would appear a reasonable approach.
Ironically, Covid-19 is not the only respiratory viral condition that peaks in winter, and the likely relaxation of social distancing guidelines will result in more people being exposed to other infections such as influenza.
Here several studies suggest that raising 25(OH)D concentrations through vitamin D supplementation in winter would reduce the risk of developing influenza and a comprehensive review of the role of vitamin D and influenza was published in 2018. It concluded that the evidence of vitamin D’s effects on the immune system suggest that vitamin D should reduce the risk of influenza.
Has Covid-19 been a distraction from the real issues around vitamin D sufficiency?
There is a real need to establish the optimal level of vitamin D supplementation in specific age groups, especially the vulnerable elderly. For example, a recent trial compared the effects of daily treatment with vitamin D or placebo for one year using blood tests of vitamin D status.
This was a randomized placebo-controlled trial with 305 community-dwelling people aged 65 years or older in Oxfordshire. The results demonstrated that daily 4000 IU (100mcg) vitamin D3 is required to achieve blood levels associated with lowest disease risks.
Then, consider that the UK Scientific Advisory Committee for Nutrition has set the lowest level for defining sufficiency (10 ng/ml or 25 nmol/L) of any national advisory body or scientific society and consequently recommends supplementation with 10 micrograms (400 IU) per day.
Here a paper just published by UK researchers, highlighted that a search for published evidence to support this recommendation was completely unsuccessful.
They argue there is considerable evidence to support the higher level for sufficiency (20 ng/ ml or 50 nmol/L) recommended by the European Food Safety Authority and the American Institute of Medicine. As a result, greater supplementation (20 micrograms or 800 IU per day) is essential.
Given that Serum 25(OH)D concentrations in the UK typically fall by around 50% through winter, these authors believe that governments should urgently recommend supplementation with 20–25 micrograms (800–1,000 IU) per day.
Personalised nutrition – a future game changer
While ‘upping’ our levels of vitamin and minerals are essential to fuel our health and wellness, especially vitamin D, there is now a wealth of evidence to suggest a more personalised basis in order to ensure optimal nutrition balance whatever our age.
Researchers have also identified significant inter-individual responses to supplementation, that suggest higher than current recommended reference intakes are needed, but which can only be identified as a result of monitoring people’s dietary status.
Finally, medicines strip our bodies of vital nutrients, especially vitamin D. The classes of medications that affect vitamin D status are significant and range from anticonvulsants to certain antihypertensive and diabetes drugs, as well as corticosteroids, and those used to treat gastric reflux, to name but a few. Moreover, as many of these drugs are co-prescribed to treat multiple co-morbidities, especially in the elderly, their cumulative impact can further add to issues of vitamin D deficits or deficiencies.