Hello! Yes, we are familiar with this paper, and in fact, this idea is repeated again and again when we discuss the importance of vitamin D and the inadequacy of current vitamin D recommendations. We believe that the current recommendations for vitamin D supplementation (600-800 IU) are far too low to help the majority of individuals to reach healthy vitamin D levels. That is why we recommend supplementing with between 5,000-10,000 IU per day in order to achieve healthy vitamin D levels (40-80 ng/ml).
Ng/mL of 25-0H is adequate at about 20 ng/mL blood levels per the IOM last I saw. 50 ng/mL would be pretty high. Anything over 38 or 39 ng/mL wasn’t as good as between about 20-38 ng/mL for bone rebuilding for instance and less adverse events. Check PubMed and various studies. More bone fractures occurred at blood levels of 25 (OH) D at 40 and above ng/mL. I’m writing an article on osteoporosis, and have been reviewing clinical trials. Supplementing with over 1,000 IU of D3 (up to 2,000 IU) was good and did prevent or reduce fracture rates somewhat in large studies, many done overseas, various continents. I would suggest not taking more than 2,000 IU a day without subsequent repeat testing, or on the advice of someone’s personal MD, due to various side effects. Taking D3 after 2pm, or even after noon, probably not a great idea either. One study I looked at had people taking melatonin (low dose) and D3 at bedtime, with calcium I think. After 2 years the folks were going to be reviewed by DEXA/NTX/bone markers, maybe even X-rays re: bone density. I thought taking the “sunshine” vitamin along with the “sleep hormone,” was a bit off. I take just as daily routine, a multivitamin about 20 min prior to lunch (ie a hot, large meal) with a half a glass of good water (filtered, or bottled) and the vitamin has calcium and D3 in it. Earlier in the day if I’m not going outdoors much, or it’s cloudy say, or in the winter, I take another 500-600 IU D3 along with some calcium and herbs, and a handful of almonds or nuts (good fats). I get between 500 IU and 1000 IU in the summer, and a bit more for the late winter days–March and April say before the summer sun is in effect. We need to look at “aging” bone and bone structure more along with D3 effects. The body loves “balance,” balance in food stuffs, hearty whole foods, and surely some sunshine if it works into our schedule. Walking with friends before or after lunch exposes us a bit to sun, works muscle and bone. Just a fun walk or even a work break out in the sun for 10-20min before 3pm say in the summer. I’m sure D production is all part of healthy living, but we can use some caution too. D3 at bedtime may be keeping some people awake at night, or making SWS, deep sleep less accessible, not sure. It’s a great field for any scientists coming up.