If you are reading this blog, I am sure that you are familiar with the role of vitamin D in promoting healthy bones and a healthy cardiovascular system as well as reduced risk for diabetes. Additional studies suggest that low vitamin D may be associated with neurodevelopmental disorders. New research just added one more surprise benefit for vitamin D supplementation – vitamin D deficiency in pregnant mothers is linked with autistic traits in the child a few years down the track.
The researchers at Australia’s University of Queensland and the Erasmus Medical Centre in the Netherlands examined around 4,200 blood samples from pregnant women and their children and discovered a link between autism and low levels of vitamin D. More specifically, they found that pregnant women who were vitamin D deficient at 20 weeks gestation were more likely to have a child with autistic traits by the age of six.1
The result from this Queensland study seems to support the conclusion from a previous study published in the Journal of Pediatric Neurosciences in 2014, which revealed that Vitamin D deficiency was higher in autism children compared to healthy children.2 The case–control study conducted between June 2011 and May 2013 surveyed a total of 508 children, 254 of autism and 254 of healthy children. The analysis revealed that Vitamin D deficiency was higher in autism children compared to healthy children.
Most of the vitamin D that we rely on comes from the sun. But things like air quality, long and cold winters at higher latitudes or simply covering up to avoid dangerous uv exposure can limit the amount of vitamin D people draw from sunlight. Rather than taking in more sunlight and, with it, the heightened risk of skin cancer, the researchers suggest that taking vitamin D supplements may be a better path forward.
Thanks for reading.
Dr. Connie Wan
- Vinkhuyzen, A. E. et al. Gestational vitamin D deficiency and autism-related traits: the Generation R Study, Molecular Psychiatry November 29, 2016; doi: 10.1038/mp.2016.213
- Bener, A. et al. Is high prevalence of Vitamin D deficiency evidence for autism disorder?: In a highly endogamous population, J. Pediatr Neurosc. 2014 Sept-Dec; 9(3) 227-233.
Vitamin D – the “sunshine vitamin” – is known to benefit bone and muscle health by promoting calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts. A major global study led by Queen Mary University of London (QMUL) added one more benefit confirming Vitamin D’s role in protecting against acute respiratory infections including colds and flu.
The results, published in The BMJ, are based on a new analysis of raw data from around 11,000 participants in 25 clinical trials conducted in 14 countries including the UK, USA, Japan, India, Afghanistan, Belgium, Italy, Australia and Canada. The analysis of pooled raw data from each of the 10,933 trial participants has yielded the first definitive evidence that vitamin D protects against respiratory infections.
The analysis showed that the Vitamin D baseline level and supplementation schedule affect vitamin D’s protective effects with the effects being strongest in those who have the lowest vitamin D levels and when supplementation is given daily or weekly rather than in more widely spaced doses. Specifically, daily or weekly supplementation of vitamin D halved the risk of acute respiratory infection in people with the lowest baseline vitamin D levels, below 25 nanomoles per litre (nmol/L). People with higher baseline vitamin D levels also benefited, although the effect was more modest with 10 per cent risk reduction. Overall, the reduction in risk of acute respiratory infection induced by vitamin D was on a par with the protective effect of injectable flu vaccine against flu-like illnesses.
Previous studies have suggested that vitamin D may protect against respiratory infections by boosting levels of antimicrobial peptides — natural antibiotic-like substances — in the lungs. Results of the QMUL study fit with the observation that colds and flu are commonest in winter and spring, when levels of vitamin D are at their lowest. They may also explain why vitamin D protects against asthma attacks, which are commonly triggered by respiratory viruses.
So what’s the take home lesson? Taking vitamin D supplement on the regular basis could be a highly cost-effective way to protect you and your family against acute respiratory infections especially in wintertime, in addition to warding off the osteoporosis and supporting your teenager’s growth spur.
The study was conducted by a consortium of 25 investigators from 21 institutions worldwide and funded by the National Institute for Health Research.
Thanks for reading.
Dr. Connie Wan
Adrian R Martineau, David A Jolliffe, Richard L Hooper, Lauren Greenberg, John F Aloia, Peter Bergman, Gal Dubnov-Raz, Susanna Esposito, Davaasambuu Ganmaa, Adit A Ginde, Emma C Goodall, Cameron C Grant, Christopher J Griffiths, Wim Janssens, Ilkka Laaksi, Semira Manaseki-Holland, David Mauger, David R Murdoch, Rachel Neale, Judy R Rees, Steve Simpson, Iwona Stelmach, Geeta Trilok Kumar, Mitsuyoshi Urashima, Carlos A Camargo. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ, 2017; i6583 DOI: 10.1136/bmj.i6583