You may remember the public health slogan, "Vitamin D helps build strong bones". This message could be seen on colorful school posters and heard on radio and television programs as early as the1950s. Getting enough Vitamin D was a major health issue, primarily for its role in preventing childhood rickets

Simon and Garfunkel [and later, The Bangles] had it right. Winter light is hazy - it's more diffuse. The sun is lower in the sky and the sun's rays reach the Earth at an angle, losing much of their power. And of course, there's less sunlight during each 24-hour day of winter than during the rest of the