Some people can tolerate Vitamin D levels above 50, so I wouldn't set that as an absolute cutoff - a Vitamin D in the 50s is good for many people, but I definitely don't want to see it above 70. Taking a higher dose for a short period of time is completely acceptable, as long as it doesn't become something that you stay on for years. It is really hard, if not impossible, to get toxic levels of Vitamin D solely from the sun or diet. I only see it with people taking supplements. And usually it's not a low dose of supplements. (And actually, many people don't even realize that they are getting high doses of Vitamin D. It is added to a lot of vitamins and supplements - so that supplement you take for hair growth may contain a few thousand units of Vitamin D, for example. I ask everyone to get out all of their supplements and look through for vitamin D.) In general, getting vitamins and minerals from diet is preferable to getting from supplements.