Sunshine vitamin fails to boost kids’ intelligence
MedWire News: High levels of vitamin D, the so-called "sunshine vitamin," do not boost kids' brainpower, a study of more than 3000 children has found.
The findings contrast with previous research that linked higher levels of vitamin D to enhanced intelligence in adults, leading the authors to propose that the benefits of the vitamin may not emerge until later in life.
Vitamin D can be produced by the body in response to sunshine or consumed in the diet via fish, eggs, mushrooms, and other vitamin-enriched products.
In the latest research, a team of scientists at the University of Bristol, UK, led by Dr Anna-Maija Tolppanen, studied 3171 children. They all had their blood tested for vitamin D levels at the age of 9 years.
Then, at the ages of 13 and 16 years, the children's school performance was assessed based on their grades in English, mathematics, and science.
Dr Tolppanen and colleagues found that the children with higher vitamin D levels fared no differently to their classmates with lower vitamin D levels in maths or science exams.
Furthermore, children with higher vitamin D levels actually did worse in their English exams than those with lower vitamin D levels. This is the opposite of what would be expected based on studies involving adults, say the researchers.
One explanation for the surprise result could be that the benefits of vitamin D on brainpower do not become apparent until adulthood, Dr Tolppanen and colleagues suggest. In other words, cumulative lifelong exposure to high levels of vitamin D may be needed to boost brainpower to a measurable extent.
Another explanation is "reverse causality," whereby less intelligent people may spend less time outdoors, or have a diet lower in vitamin D, than more intelligent people.
Whatever the explanation, the latest research suggests that children should not be exposed to sunshine or given vitamin D supplements in order to boost their academic performance, say the researchers.
This is particularly important given the established health dangers of excessive sun exposure - and in particular, the established link between sunburn and skin cancer.
The authors conclude: "Our results suggest that protection of children from ultraviolet B rays [sunshine] which has been associated with low levels of vitamin D, but which protects against skin damage and skin cancer, is unlikely to have any detrimental effect on academic achievement."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Joanna Lyford