The Big Vitamin D Mistake

Introduccion

The incidence of type 1 diabetes (T1D) has been doubling every 20 years. In Finland, the recommendation for daily vitamin D supplementation was gradually reduced from 4000-5000 IU in 1964 to 400 IU in 1992. Concomitantly, T1D increased by 350% in those aged 1-4 years, 100% in those aged 5-9 years, and 50% in those aged 10-14 years [1]. However, since 2006, T1D has plateaued and decreased after an increase in serum 25-hydroxyvitamin D (25[OH]D) after the authorities’ decision to fortify all dietary milk products with cholecalciferol [2]. Moreover, the worldwide association of ultraviolet (UV)-B light and vitamin D status with T1D and multiple sclerosis is now more than evident.

Main Body

The incidence of type 1 diabetes (T1D) has been doubling every 20 years. In Finland, the recommendation for daily vitamin D supplementation was gradually reduced from 4000-5000 IU in 1964 to 400 IU in 1992. Concomitantly, T1D increased by 350% in those aged 1-4 years, 100% in those aged 5-9 years, and 50% in those aged 10-14 years [1]. However, since 2006, T1D has plateaued and decreased after an increase in serum 25-hydroxyvitamin D (25[OH]D) after the authorities’ decision to fortify all dietary milk products with cholecalciferol [2]. Moreover, the worldwide association of ultraviolet (UV)-B light and vitamin D status with T1D and multiple sclerosis is now more than evident.

Conclusion

Unfortunately, medicine took a very long time to realize that vitamin D is not simply a vitamin that prevents rickets. For that purpose, 400-600 IU/d may be enough. However, we know today that vitamin D is a powerful nuclear receptor-activating hormone of critical importance, especially to the immune system. With the available data mentioned above, the proposed doses would probably suffice to maintain vitamin D levels around or over 75-100 nmol/L, with practically zero risk of toxicity. Undeniably, further studies are needed to clarify the optimal supplementation of vitamin D, although it is uncertain whether a universal recommended dietary allowance is feasible. Meanwhile, actions are urgently needed to protect the global population from the threats posed by vitamin D deficiency.