THE GOOD NEWS
is we know that vitamin D improves bone mineral density.
THE BAD NEWS
is that it can be hard to get enough vitamin D from natural sources alone.
We get most of our vitamin D through exposure to sunlight.
But this is in short supply in cooler, cloudy climates.
Even in hot countries, people are rightly advised to cover up
or wear sun-screen to protect the skin, reducing their ability
to absorb vitamin D from the sun.