I ran across a suggestion that mega doses of D3 (like 50,000 IU daily) is helpful for a variety of maladies including obesity.

Is there any serious research to support this contention?

There is some but it never helped me lose weight.

Research published by Grassroots Health from the D*Action study shows that universal intake of up to 40,000 IU vitamin D per day is unlikely to result in vitamin D toxicity.

http://www.ncbi.nlm.nih.gov/pubmed/21378345

http://www.grassrootshealth.net/garland02-11

Dr. Joe Prendergast, an endocrinologist /diabetologist has managed over 1500 diabetic patients and, in the last decade, not one of his patients has had a stroke or heart attack. Only one has even been hospitalized! His secret—50,000 units of Vitamin D3 daily. Dr. Joe further reports:

* Reversal of advanced coronary disease
* Reversal of advanced lung disease
* Cure of multiple sclerosis
* Cure of amotrophic lateral sclerosis
* Regression of rheumatoid arthritis
* Improvement in allergies
* Control of many cancers
* Reversal of osteoporosis
* Prevention of influenza
* Cure of depression & other mental disorders
* Hashimoto’s hyperthyroidism

In summary, the evidence for safety and remarkable efficacy of Vitamin D3 suggests that virtually ALL adults should probably take 50,000 units of D3 daily. This is certainly true for those with virtually any illness.

http://enews.endocrinemetabolic.com...y-diseases.html

This site is down for maintenance but it should give you any listing if any studies have been done.

http://www.vitamindwiki.com/