Well a search of
PubMed was interesting. Specifically
this paper which was an analysis of many papers/studies of melatonin.
So the idea, for older adults who are not producing as much melatonin, is to keep the doses fairly low. So at the lowest rate mentioned above, 0.1mg/kg, that would work out to approx 9mg of melatonin for me. I have been taking approx. 11-12 a night recently. What is interesting also is that it appears that melatonin supplementation was more effective in older adults, as their serum levels remained higher. Or another way of looking at it is that younger adults were not as affected by melatonin supplementation as oral doses did not result in elevated serum levels. This could mean that younger adults excreted the melatonin they did not need? or that they actually used the supplemented melatonin and so less was in the blood? I can't say I know enough about physiology to know which explanation, or other explanation, would be more correct.