The more conservative Endocrine Society published their clinical practice guideline on the evaluation, treatment & prevention of vitamin D deficiency back in July in their JCEM. They're comfortable with the use of 25OH vitamin D as the initial screening assay but don't recommend its use in those not at risk for deficiency.
On the surface, this is a reasonable statement but realistically, there are very few of us who are low risk and get enough sun exposure daily throughout the year without an sunscreen or sunblock. Studies of the general population in traditionally sunny geographic areas such as Arizona, Florida & Hawaii demonstrate a higher than expected rate of vitamin D deficiency.
Ironicially, a systematic review & meta-analysis published in the same issue of JCEM found no cardiovascular benefit from vitamin D in 51 randomized controlled trials. And a quick summary published earlier this week reviewed the paucity of randomized controlled trials demonstrating non-osteoporotic benefit.
worry about poor manufacturing leading to toxicity.