Sure feels like it. Been taking 2000 IU and went up to 4000 today. Whoah. Never actually felt a vitamin before...
I don't think so... 4000 IU is a pretty normal dosage, not too much at all. Jack Kruse recommends 5000 IU and some people even go as high as 10,000 IU without any effects. Must be something else. Did you do anything different today?
I've experienced this before, but not anymore. It was when I switched from 5k to 10k.
It was WOW! I feel great! Like you went into a gear that you didn't know you had. It waned though and I never got it again. :(
I've taken up to 40,000 IU per day for a week and didn't feel much of a difference, but if you're severely deficient in vitamin D then maybe it could make you feel that way but I doubt it, but it could be something else you ate or took today. Vitamin D is a hormone so its effects are usually gradual and subtle since it works on the level of gene expression for many genes.
I have noticed the same thing whenever I've upped my vitamin D dosage, whether from 5,000 to 10,000 or from 10,000 to 15,000 IU per day. I'm guessing it has something to do with your brain chemistry and a temporary upregulation of some pathway, which has a negative feedback loop and subsequently returns to normal.
My Vitamin D was only 17 so got a prescription for 50k 1/week. After 1 mo it was up to the mid-20s and I concur: energy levels were great! Another 4 doses and it was up to low 30s, at which point I stopped and switched to a lower OTC dose.
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