Sunday in Washington had all the ingredients of winter, wind, cold and snow. Seven days from the solstice, winter seemed to be already here.

At close: December 12 at 4:00:02 PM EST ...

Vitamin D3 maintains higher and more stable blood levels than vitamin D2. Vitamin D2 comes from plant sources like mushrooms and yeast, while D3 comes from animal sources and sunlight. Supplements can ...

A 25-hydroxyvitamin D test checks if your body has too much or too little vitamin D. The test involves a simple blood draw, and you don't need to fast beforehand. Risks from the test are rare but ...