blamebrampton

It's my own fault: I know not to watch television, and I especially know not to watch commercial television news.

But still ... Channel 10 has just ran another 'Australians are short of Vitamin D!' story. Now this in itself is not my problem: there are some parts of Australian society that do have very low levels (generally the elderly and people who simply do not go outside). However, this wasn't how the ads ran nor how the presenter introduced the story.

This is: "There's a new health warning about the sun! Apparently we're not getting enough of it!"

This story has been floating around for the past few years, since a position statement on Australian levels of Vitamin D was published in the Medical Journal of Australia. In it, we read:

Groups at risk of vitamin D deficiency
Older people who are institutionalised or housebound are at a particularly high risk of vitamin D deficiency. For example, up to 80% of women and 70% of men living in hostels or nursing homes in Victoria, New South Wales and Western Australia were frankly deficient in vitamin D, and 97% had a 25-OHD level below the median value of the healthy reference range.8,9 There also appears to be a significant prevalence of mild vitamin D deficiency in younger adults, particularly during winter.5

Groups for whom low vitamin D levels have been documented include:
* older people in low- and high-level residential care;8-10
* older people admitted to hospital;11
* patients with hip fracture;12,13
* dark-skinned women (particularly if veiled);14-16 and
* mothers of infants with rickets (particularly if dark-skinned and veiled).17

And their solution:

Exposure to sunlight: For people living in Australia and New Zealand, the main source of vitamin D is through exposure to sunlight. It has been shown that whole body exposure to 10–15 minutes of midday sun in summer (about 1 minimal erythemal dose [MED], or the amount of sun exposure which just produces a faint redness of skin) is comparable to taking 15 000 IU (375 μg) of vitamin D (cholecalciferol) orally.2 On this basis, exposure of hands, face and arms (around 15% of body surface) to around 1/3 MED should produce around 1000 IU of vitamin D (cholecalciferol). The amount of sun exposure to produce 1/3 MED varies with latitude, season, time of day and skin type (Box 1).

[Snip]

It is therefore prudent to expose hands, face and arms to 1/3 MED of sunlight most days. Box 1 shows approximate exposure times for various regions, months and skin types. But there is a caveat: deliberate exposure to sunlight between 10:00 and 14:00 (or 11:00 and 15:00 daylight saving time) in the summer months is not advised. If adequate sunlight exposure to generate sufficient endogenous cholecalciferol is not possible, then a vitamin D supplement of at least 400 IU (10 μg) per day is recommended.

Most of you have never lived in Australia, but let me just say that the above is basically the advice everyone is given here. Stay out of the sun in the middle of the day, get a few minutes on your arms and legs early or late in the day most days. And that is a few minutes, 5-8 in summer, even in Tassie. The only people who need more are dark-skinned people and those who have darker skin and wear the veil.

Happily, I can report that the journalist's actual report was more moderate and differentiated the recommended doses for skin colours and for those who wore more clothing for cultural reason. It also finished with a responsible note, saying that no one was recommending we sunbathe over here, rather that five minutes a day, five times a week, or a vitamin supplement would be ample.

So a gold star to Amber Muir, and a smack to the back of the head to the Channel 10 production team.

In happier news, HAPPY BIRTHDAY