Certain groups of people are at greater risk of not getting enough vitamin D. Here are some of them.

Nutritional science is supposed to chart a course to our healthier selves. But contradictory scientific results and interpretations can muddy the waters — and few nutrients have recently demonstrated that more clearly than vitamin D.

At one point, it seemed that everyone should be taking vitamin D supplements, and that doing so would protect against a whole host of maladies, from bone problems to heart disease and cancer. More recently, new studies appear to have debunked many of those claims.

But a closer look at the research reveals a more nuanced message around vitamin D supplements: They can be key to correcting deficiencies, though people who already have enough — which is most of the American public — are generally unlikely to see benefits from taking large doses. Experts have come to worry about supplement enthusiasts overdosing in the belief that more is better or, at the other extreme, some nutrient-deprived people shunning them altogether.

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Scris de: Katarina Zimmer

Categorie: Ştiri ştiinţă - engleză

Creat: 21 Aprilie 2024

Contrary to the commonly-held view, the brain does not have the ability to rewire itself to compensate for the loss of sight, an amputation or stroke, for example, say scientists from the University of Cambridge and Johns Hopkins University.

So many times, the brain’s ability to rewire has been described as ‘miraculous’ – but we’re scientists, we don’t believe in magic. Tamar Makin

Writing in eLife, Professors Tamar Makin (Cambridge) and John Krakauer (Johns Hopkins) argue that the notion that the brain, in response to injury or deficit, can reorganise itself and repurpose particular regions for new functions, is fundamentally flawed – despite being commonly cited in scientific textbooks. Instead, they argue that what is occurring is merely the brain being trained to utilise already existing, but latent, abilities.

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Scris de: Craig Brierley

Categorie: Ştiri ştiinţă - engleză

Creat: 07 Aprilie 2024

Hedgerows in mid-February might have traditionally appeared white with snow; this year the white was the work of blackthorn blossoms – a harbinger of spring. Although a welcome sign after a wet and gloomy winter, the early flowering brings unease for experienced season watchers. Has this plant always flowered in mid-February, I wondered, or is something changing?

Fortunately, the science of recording and understanding seasonal events, phenology, has a long history in Britain. Robert Marsham, an 18th-century naturalist, kept records of the appearance of the flowers, birds and insects in his Norfolk village as far back as 1736. Marsham’s descendants continued the recording until 1958. The Woodland Trust maintains the tradition with Nature’s Calendar, a scheme in which members of the public are invited to record various seasonal events.

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Scris de: Paul Ashton

Categorie: Ştiri ştiinţă - engleză

Creat: 03 Martie 2024