Vitamin D deficiency remains a serious problem in Britain – are we identifying people at risk early enough?
New scientific Position Paper calls for urgent review of UK vitamin D guidance as evidence highlights persistent deficiency, declining dietary intakes and preventable illness.
Almost one in four UK teenagers and nearly one in five adults has vitamin D levels below the UK’s current threshold for increased risk of poor musculoskeletal health, according to latest National Diet and Nutrition Survey (NDNS) figures cited by a multidisciplinary group of scientists and clinicians.
Despite decades of public health guidance, vitamin D deficiency remains a significant challenge in modern Britain, with potentially serious consequences for bone health, particularly among children, young adults, pregnant women and people from higher-risk population groups, including those from ethnic minority backgrounds.
Now, a coalition of leading clinicians, nutrition scientists, public health experts and patient advocates is asking a fundamental question: are we identifying people at risk early enough to prevent avoidable illness?
In a new scientific Position Statement published in Frontiers in Endocrinology, ACT NOW Vitamin D calls for an urgent review of the UK’s current vitamin D deficiency threshold of below 25 nmol/L, proposing that policymakers consider raising it to below 50 nmol/L.
The group argues that the existing threshold may underestimate the wider population at risk and limit opportunities for earlier prevention. A revised threshold could also bring UK practice into closer alignment with several international clinical frameworks.
Human cost
For Saskia Reeves-Priestley, a Londoner in her twenties, vitamin D deficiency was not something she had ever expected to experience.
A keen footballer, Saskia suddenly became unwell at work and collapsed. Following medical investigations, she was found to have severe vitamin D deficiency and was subsequently prescribed vitamin D by her GP. Her experience illustrates how vitamin D deficiency can affect young, active people who might otherwise consider themselves healthy.
Saskia:
“I had no idea that I might be low in vitamin D. I was blown away by it. Nor did I know that low vitamin D could affect the whole of my body in such a dramatic way; it was a shocking experience. It’s not something people know enough about in the UK.
‘’We need to help others appreciate the vital importance of vitamin D for health.”
Clinical specialists within ACT NOW Vitamin D warn that the consequences can be particularly serious for children and pregnant women, with nutritional rickets and osteomalacia remaining preventable but persistent problems.
Dr Suma Uday, Paediatric Endocrinologist and Clinical Lead for ACT NOW Vitamin D, has extensive experience in managing vitamin D deficiency and its consequences in infants, children and families. She is a Consultant Paediatric Endocrinologist at Birmingham Children’s Hospital and an Honorary Clinical Associate Professor at the University of Birmingham.
“Vitamin D deficiency is not simply a number on a blood test. We continue to see children and families affected by serious bone disease, including nutritional rickets and osteomalacia. In its most severe forms, vitamin D deficiency can have life-threatening consequences, including seizures, heart failure and death.
“These are conditions we should be working to prevent. Greater awareness, earlier recognition of risk and more consistent public health approaches such as supplementation of high-risk groups could make a real difference, particularly for vulnerable mothers and families.”
Why is vitamin D deficiency still so common?
Vitamin D is often called the ‘sunshine vitamin’ because sunlight exposure enables the body to produce it naturally. However, in the UK, limited sunlight during autumn and winter, changing lifestyles and dietary patterns, and demographic factors create persistent challenges for maintaining adequate vitamin D status.
Vitamin D occurs naturally in relatively few foods, including oily fish, eggs and some animal-derived products. Dietary supplements and fortified foods can therefore provide important additional sources.
Recent analyses of national dietary surveys across four European countries, including the UK, have identified substantial declines in vitamin D intake over approximately two decades.
Among UK adults with the lowest dietary intakes, declines of up to 50% were observed in some population groups.
This is particularly concerning because these individuals may already have very limited dietary sources of vitamin D.
At the same time, the latest UK NDNS findings cited by ACT NOW Vitamin D report vitamin D concentrations below 25 nmol/L in:
- 23% of young people aged 11-18
- 18% of adults aged 19-64
- 12% of adults aged 65 and over
These findings raise important questions about whether current approaches to vitamin D awareness, prevention and population monitoring are sufficient.
People with darker skin pigmentation, limited sunlight exposure, obesity and certain other risk factors may face additional challenges in maintaining adequate vitamin D status.
Is Britain’s vitamin D threshold too low?
The UK’s current population threshold of below 25 nmol/L was established to identify increased risk of poor musculoskeletal health, including conditions associated with severe vitamin D deficiency.
ACT NOW Vitamin D argues that focusing primarily on this low threshold may overlook a much larger population with vitamin D concentrations between 25 and 50 nmol/L, for whom prevention and risk assessment may also be important.
The group is therefore calling for a scientific and public health review of whether a threshold of below 50 nmol/L would provide a more appropriate basis for identifying risk and supporting earlier preventive action.
Professor Martin Hewison, Lead Author (Emeritus Professor of Molecular Endocrinology; Birmingham University):
“Vitamin D deficiency remains a significant and largely preventable public health problem in the UK. Yet our current approach may be identifying risk too late and underestimating the scale of the challenge.
“We believe it is time to reconsider whether the UK’s definition of vitamin D deficiency is sufficiently protective, particularly for children, young adults and vulnerable population groups.
“This is not simply about changing a laboratory number. It is about strengthening prevention, improving awareness and ensuring that public health policy reflects the best available scientific and clinical evidence.”
ACT NOW Vitamin D emphasises that its proposal does not imply that higher vitamin D concentrations will necessarily deliver additional health benefits for everyone. Evidence for benefits beyond established skeletal and musculoskeletal outcomes remains an area of scientific investigation.
Rather, the group believes that the existing threshold merits careful reassessment in light of current population data, clinical experience and international scientific perspectives.
Call for action: putting prevention first
ACT NOW Vitamin D is calling for renewed collaboration between government, healthcare professionals, public health authorities, researchers and patient advocates. The group believes that a review of the current threshold could provide an opportunity to strengthen public awareness, improve identification of vulnerable groups and inform future approaches to supplementation, food fortification and health inequalities.
Its overarching message is straightforward:
Vitamin D deficiency should not have to progress to serious illness before prevention becomes a priority.
The Position Statement aims to stimulate an evidence-informed national discussion about how the UK can better protect vitamin D health across the life-course.
About ACT NOW Vitamin D
ACT NOW Vitamin D is an independent multidisciplinary collective of clinicians, scientists, public health experts and patient advocates committed to improving vitamin D health in the United Kingdom. The group seeks to advance scientific understanding, raise awareness and encourage evidence-informed approaches to reducing vitamin D deficiency and preventable disease.
Acknowledgements
ACT NOW Vitamin D gratefully acknowledges the Council for Responsible Nutrition UK (www.crnuk.org) for facilitating and supporting the collective’s founding meeting and encouraging multidisciplinary collaboration.
Notes to Editors
- The ACT NOW Vitamin D Position Statement was published in Frontiers in Endocrinology in 2026.
- The group calls for consideration of raising the UK vitamin D deficiency threshold from below 25 nmol/L to below 50 nmol/L.
- The current UK population threshold relates primarily to musculoskeletal health risk.
- The Position Statement addresses vitamin D status, public health surveillance, prevention, clinical practice and health inequalities.
- The dietary intake findings are drawn from separate analyses of national dietary surveys and should not be confused with measurements of blood vitamin D concentrations.
Scientific publication: ACT NOW Vitamin D Position Statement – Frontiers in Endocrinology