“Little evidence” of vitamin D for COVID-19, conclude UK health bodies in rapid update

17 Dec 2020 --- Rapid guidance from UK health bodies have concluded that “there was little evidence for using vitamin D supplements to prevent or treat COVID‑19.” This has been met with mixed reactions by many experts in this space.

The National Institute for Health and Care Excellence (NICE), Public Health England (PHE) and the Scientific Advisory Committee on Nutrition (SACN) have recommended emphasizing the existing guidance for people to take vitamin D supplementation to maintain bone and muscle health.

The rapid review update also states that evidence suggests that there may be some benefit from daily, low-dose vitamin D supplementation in reducing risk of acute respiratory tract infections (ARTI). However, the size of any potential benefit of vitamin D in reducing ARTI risk may be small.

Additionally, the beneficial effect of vitamin D supplementation in reducing ARTI risk was only observed in people between the age of one to 16 years. No beneficial effects were observed at more than 25 µg per day, or when vitamin D supplementation was weekly or monthly. 

SACN also says that research is “urgently” required on vitamin D and risk of acute respiratory tract infections in Black, Asian and minority ethnic groups and people who are overweight or obese.

No changes to prior guidance
This update to previous guidance given in June was carried out at the request of the UK’s health minister, Matt Hancock, following calls for a deeper investigation. Last month, it was announced that England would offer 2.5 million people deemed vulnerable to COVID-19 free vitamin D supplements for the winter.

Ultimately, SACN does not recommend any changes to the reference nutrient intake. The UK government advice includes:

• Everyone over the age of four should consider taking a daily supplement containing 10 μg (400 IU) of vitamin D between October and early March because people do not make enough vitamin D from sunlight in these months.
• Everyone over the age of four should consider taking a daily supplement containing 10 μg of vitamin D throughout the year if they have little or no sunshine exposure or if they have dark skin.
• Babies from birth to one year should have a daily supplement containing 8.5 to 10 μg of vitamin D throughout the year if they are breastfed or consume less than 500 mL of infant formula a day.
• Children between the age of one to four should have a daily 10 μg supplement throughout the year. 
• Some people have a medical condition that means they cannot take vitamin D or should take a different amount from the general population.

The health bodies also recommend that vitamin D supplementation is not offered to people solely to treat or prevent COVID‑19, except as part of a clinical trial.No data was available about whether vitamin D’s reported effects equally to populations from Black, Asian and minority ethnic groups or people that are overweight or obese. 

“Hugely disappointing”
Some experts have reacted negatively to the conclusions. Martin Hewison, professor of molecular endocrinology at the University of Birmingham, says the new guidance is “hugely” disappointing. 

“I am sure that this response will be echoed by many other vitamin D researchers in the UK and worldwide,” he states. 

He points out that the UK has the lowest vitamin D supplementation recommendations in the world, despite recognition of the prevalence of vitamin D-deficiency in the UK. He hopes to see recommendations increase to 800 IU per day. 

Meanwhile, Dr. David Richardson, founder and director of Dr Nutrition and visiting professor of food bioscience at the University of Reading, says that the guidelines should include a greater push to unwrap the extent of vitamin D deficiency in the general population and vulnerable groups. 

“Not a silver bullet”
However, other scientists in this space have come out in support of the guidance. 

“The NICE rapid guideline on COVID-19 and vitamin D accurately and succinctly summarizes the existing evidence. Vitamin D is indeed important for bone and muscle health, and the national guidelines on supplementation should be followed,” says Dr. Claire Hastie, lecturer in public health at the University of Glasgow and Health Data Research UK. 

“This report, which considers all relevant evidence, is important as it reminds the public that on the basis of available evidence, we absolutely cannot say that vitamin D is a ‘magic bullet’ against COVID-19 infection,” adds Naveed Sattar, professor of metabolic medicine, University of Glasgow.

He continues that the reality is far from it, and only ongoing trials will lead us to the truth. This is because nearly all available vitamin D data linked to COVID-19 is observational and “riddled” with uncertainty, so it’s impossible to determine cause and effect.

By Katherine Durrell