U shape is good and bad

I did not expect that serum vitamin D levels are associated with mortality at both ends of the distribution as now shown by Dorup et al.

Out of 247,574 a total of 16.645 subjects died in the ensuing 0 -7 years. … 25-hydroxyvitamin D level of 70 nmol/L was associated with the lowest cardiovascular disease mortality risk … At the higher extreme (125 nmol/L), the hazard ratio of cardiovascular disease mortality was 1.3 (95% CI 1.2-1.4), with similar risk among men and women.

Following our first paper on U shaped vitamin D effects there are now many more papers show that effect. Vitamin D is not just good or bad, it is both depending on timing, dose, application, whatever.