[jlcgull]

More truth than hype in this case. The modern indoor lifestyle and diet are not very conducive to maintaining the requisite levels.

Vitamin D comes in many forms -- and not all are equal: http://en.wikipedia.org/wiki/Cholecalciferol

[robg]

Indeed. The D3 form is one you want. I actually had a endocrinologist prescribe the D2 form. Luckily my nutritionist has been following the literature for years.

[carbocation]

Both forms are suffiecient to cure rickets.

[dgordon]

And that incredibly low standard is also how the FDA set the "recommended daily allowance." Similar things are true for most other vitamins and minerals, as I recall.

Also, D2 causes overdose effects pretty easily, but you can take big multiples of the "RDA" in D3 (I think 10,000 IU/day for months for vitamin D deficiency has been mentioned) for quite a while without overdosing.

[carbocation]

> you can take big multiples of the "RDA" in D3 (I think 10,000 IU/day for months for vitamin D deficiency has been mentioned) for quite a while without overdosing.

That's actually a problem, as people can become accustomed to taking large doses and then not understand why problems are occurring when they start way down the road.