No clear evidence Vitamin D supplements reduce death from disease

  • April 2, 2014
No clear evidence Vitamin D supplements reduce death from disease

A new large-scale research study co-led by Dr Rajiv Chowdhury shows that vitamin D supplementation, when administered alone, does not reduce mortality among older adults.

A new large-scale research study co-led by a Gates Cambridge Alumnus shows that vitamin D supplementation, when administered alone, does not reduce mortality among older adults.

However, when examined by type of supplementation, the researchers did find that vitamin D3 alone reduced mortality by 11 per cent. The scientists stress that additional research is needed.

The new research,  which examined data from nearly 100 studies, is published today in the British Medical Journal (BMJ). It was conducted by an international team of researchers and co-led by Dr Rajiv Chowdhury at the University of Cambridge’s Department of Public Health and Primary Care. He said: “With so many people touting vitamin D as a possible panacea, our study provides useful insight into the limitations of the current evidence base of vitamin D supplements and highlights where additional research is needed.”

Previous research has shown that lower levels of vitamin D in the blood are associated with a number of different diseases (to include multiple sclerosis, cancer and cardiovascular disease). However, it was not clear whether vitamin D supplementation when given alone (that is, not co-adminstered with other interventions such as calcium) would reduce the risk of deaths from various causes. In order to help clarify these associations, researchers analysed the results of 73 observational cohort studies and 22 randomised trials of both naturally circulating vitamin D and supplements (either D2 or D3).

In total, these studies involved nearly a million individuals from 26 countries and included patients with established cardiovascular disease as well as lower risk people without the disease. Additionally, differences in study quality were taken into account to identify and minimise bias.

Their analysis reinforced the observational associations of lower levels of circulating vitamin D concentrations with deaths from cardiovascular, cancer, as well as other causes, but they also found that vitamin D supplements in the trials, overall, did not reduce the risk of all-cause mortality significantly.

However, when stratified by type of supplements, vitamin D3 taken alone reduced mortality significantly by 11% among older adults. By contrast, supplementation with vitamin D2 singly had no overall impact on mortality.

Remarking on the research, Dr Chowdhury added: “Before any recommendation of widespread supplementations with vitamin D3, it is, however, essential that further clinical investigations are conducted into the optimal dosage and safety. It will also be important to examine whether D2 or D3 alone may indeed have different effects on the risk of death in different populations since the current trials were essentially based in elderly high risk populations with a variety of baseline diseases and any beneficial effects on healthy general populations are not yet known.”

More details here.

Picture credit: www.freedigitalphotos.net and Maggie Smith.

Latest News

Tracing the origins of our political beliefs

What makes some people more vulnerable to extremism than others? How do we build cognitive resilience against extreme ideologies? And how does the brain react to misinformation on social media? These are some of the key political questions that political neuroscientist Leor Zmigrod [2016] is exploring, putting the science into our understanding of radicalisation.   Leor […]

A leading woman in STEAM

A Gates Cambridge Scholar has been selected as one of the 75 leading women in Science, Technology, Engineering, Arts and Mathematics in India. Yama Dixit will feature in the second edition of the book She Is, published by the Red Dot Foundation in partnership with the Office of the Principal Scientific Adviser, Government of India to mark 75 […]

Tackling the obesity epidemic in Africa

When she left school, Paula-Peace James-Okoro [2022] intended to become a medical doctor, but after starting a degree in Biochemistry she discovered a passion for the subject and for using it to address one of the major health challenges facing Africa – obesity. She says: “In Africa, the rates of metabolic diseases, like obesity and […]

Triple win for Bill Gates Sr. Prize

For the first time three Gates Cambridge Scholars are sharing this year’s Bill Gates Sr. Prize in recognition of their outstanding research and social leadership. Kim van Daalen, Reetika Subramanian and Cynthia Okoye have been selected for the prize which was established by the Gates Cambridge Trustees in June 2012 in recognition of the late […]