The study defining vitamin D deficiency below 25 nmol/L (10 ng/mL) uses a threshold that is considered three times lower than what is generally accepted as deficient.

“One caveat I should point out that this study defined deficiency as below 25 nanom per liter or 10 mgam per milliliter so um I you know we think that that is really deficient we think that that's like 3x below the what what we consider deficient”