He's had to deal with a lot of fairly severe criticism in the past so I think is being overly cautious. It's all very well for me to point to a prolonged intake of 10,000 IU/d of vitamin D(3) poses no risk of adverse effects for adults, even if this is added to a rather high physiologic background level of vitamin D. and say you may as well aim high initially and then reduce your supplement intake after you have had a 25(OH)D test proving you are above 55ng ~ 137.5nmol/l but it's another thing for a Dr to say that as it could be interpreted as medical advice. It's still not clear how vitamin D status is associated with fat storage. On interesting theory is that when our vitamin D status drops in the winter, this is a signal for the body to store fat (and vitamin D3) to help survival through the winter. So lowering vitamin D levels are regarded by the body as time to stock up for the winter. While rising 25(OH)D indicate that summer's on the way and so we no longer need to store surplus fats.