Anomalous Vitamin D Test Results
(San Francisco, California)
I started supplementing with 2000 IU/day of vitamin D3 in January 2009. I don't know what my blood D3 level was when I started.
After seven months I tested at 30.1 ng/mL. I then increased my intake to 8000 IU/day, and eventually my tests leveled out in the 50 ng/mL range. So, I increased my input to 10,000 IU/day, and I tested in August 2011 (one year ago) at 77 ng/mL. Finally I reduced my daily input back to 8,000 IU last August.
After supplementing for one year at 8,000 IU, I tested this week expecting a result in the 50-60 range. But, to my horror, the test result came back at 30.1 ng/mL. I didn't believe the result, so I retested one day later and got a value of 34 ng/mL, probably within the normal testing error.
After nearly four years of supplementing and testing, I' right back at 30 ng/mL where I started.... and very disappointed.
I believe my problem must be one of these three:
Bad test - But I retested and Lab Corp confirmed the figure.
Malabsorbtion of the supplement - But, I had three years of predictable results as I increased my intake from 2-10,000 IU/day and achieved a level of 77 ng/mL.
The third would be a bad batch of supplement (I was using Ddrops distributed by Carlson Lab.)
I really need some direction. Thank you.