My own experience getting a too-high result from supplementing 5K IU several times a week. When it came up, my doctor said I wasn't alone and that she's seeing a lot of people come back too high.

> I took me five years just to get to something close to the lowest end of normal.

Five years of supplementing to get up to 30ng/mL? Something is wrong. Could your supplements have not actually contained any real amount of Vitamin D? Certain malabsorption disorders also reduce Vitamin D absorption, for example.

Five years is unusually long, but your case is an outlier too. Usually it will take about 3 months to rise serum levels by ~30ng/mL on 5K IU daily, though there's plenty of individual variation of course.

It's a low enough dose that if I had to choose between taking it blindly or not taking it at all if I was so depressed I couldn't get out of bed to get my levels tested, then I would do it blindly for a month or two without second thoughts.

Don't forget your K2!