I wrote an article today that won’t actually be coming out for months, but it follows one of the themes I have written about quite a lot, so I thought I would jump in now.
Scientists at the Telethon Institute have found evidence that vitamin D deficiency during pregnancy is associated with reduced language capacity in children. The sample size on this was not huge, but the study is very long term – they’ve been following children for 17 years after taking blood samples from the mothers while they were pregnant. They intend to keep going, seeing whether children affected in this way every overcome the problem, or indeed whether other issues emerge.
What we’re seeing here is part of a pattern. It appears that vitamin D is important for a lot more things than we once recognised. I’ve alluded previously to Professor John McGrath’s work from several angles linking vitamin D deficiency in childhood to schizophrenia. The scientist I interviewed also said there is plenty of evidence of an association with asthma, and of course the importance for preventing rickets has been known for a long time.
In one sense the Telthon research is good news for those who didn’t get much second hand sun. They went looking for a number of other potential problems and found no evidence of them. Nevertheless, the list of things you can get from lacking vitamin D as a foetus is getting both long and serious.
Yet it doesn’t seem the message is getting through. The mothers in the study had their blood taken almost twenty years ago. Since then vitamin D deficiency has become far more common, and it seems this is at least as true amongst pregnant mothers as the population as a whole. This is attributed to two factors.
Firstly, some people are over-reacting to the Slip, Slop, Slap message. Dr Andrew Whitehouse, who I interviewed for this story, noted that the anti-skin cancer campaign has been one of the most successful public health messages ever run in Australia. However, at least twenty years ago, most of the low levels of vitamin D were recorded amongst women giving birth in late winter or spring. In other words it wasn’t a case of mothers avoiding the summer sun, they were avoiding sunlight in winter, when it would be hard to contract skin cancer even if you tried (tropical regions excepted).
A second factor that gets talked about is the astronomically high rates of vitamin D deficiency amongst women from communities where the wearing of veils, let alone burkas, is common. It’s been noted that in the Middle East houses are traditionally built with internal courtyards so that women could have space where they could sunbathe without being seen by men outside the family, while many Australian dwellings, particularly the places immigrants live initially, lack these facilities. I wonder whether simply spending too much time, as I do, bathed in the glow of a computer screen, may not be a factor across the population as well.
I’m not sure to what extent pregnant women are made aware of these issues. One good thing is that, while a lot of the things that can go wrong in pregnancy occur before many mothers-to-be know their state, the parts of the brain that seem to depend on healthy vitamin D levels form later, so there is plenty of time for advice to be given.
However, in the wider community it is clear the message is not getting through. Evidence is emerging that lack of sunlight can be an issue later in life. I’ve done articles on signs that people are more likely to recover from cancer if they have don’t shun the sun (this appears to be only partly explained by vitamin D) and that the the omnipresent vitamin is important for multiple sclerosis prognosis. This is news to almost all the people I talk to, who tend to be relatively well educated and scientifically aware.
Even more concerning is that we don’t actually know how much vitamin D is actually needed. The level defined as deficient is that required for the formation of healthy bones. However, as one researcher admitted to me “for all we know you might need a higher dose to avoid psychosis or some other condition.” Dietary supplements, injections and even vitamin D creams are available (Whitehouse says future research will investigate the effectiveness of these options) but it might be no bad thing, come the cooler months, to linger a little longer on the sunny side of the street, park or balcony.
I am deeply aware that our society is profoundly guiltogenic for mothers and pregnant women, making them feel that if they’re not doing everything right they’re failing their children, society or both. I don’t want to add to that. But spending some time in the sun in winter or spring shouldn’t be a chore. I’d imagine a lot of women would find it rather a joy to know that they’d be doing their child good if they spent some time lying outside every sunny winter’s day.