Journal of the American College of Nutrition -- Lappe et al. 25 (5): 395 Figure 1

Click on image to view larger version.

Fig. 1. Frequency distribution of seasonally adjusted 25(OH)D values in a rural cohort of women aged 55 and older. N = 1179. The smooth curve is the best fit Gaussian curve for the distribution. (Copyright, Robert P. Heaney, 2005. Used with permission.)