Is this not the task of health ministries? Leave other decisions to doctors and not politicians or others.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2801%2906580-1/fulltext

Also, this [nutrition] should be in the hand of doctors but often the knowledge of vitamin D [and nutrition in general] had been very poor in the medical education.

Interpretation

Dietary vitamin D supplementation is associated with reduced risk of type 1 diabetes. Ensuring adequate vitamin D supplementation for infants could help to reverse the increasing trend in the incidence of type 1 diabetes.

Introduction

Exactly what causes the destruction of insulin secreting β cells in the pancreas, and thus the development of type 1 diabetes, remains unknown, though cytokines, T cells, and macrophages have all been implicated.1 In vitro, vitamin D acts as an immunosuppressive agent, reducing lymphocyte proliferation and cytokine production.2 Furthermore, in animals, the administration of vitamin D (1,25 (OH)2D3) seems to prevent development of type 1 diabetes.34Factors in infancy can affect the risk of development of diabetes in later life. The results of a large case-control study suggest that vitamin D supplementation during early childhood can prevent type 1 diabetes.5 Another study also found an inverse relation between maternal use of cod liver oil during pregnancy and the frequency of type 1 diabetes in their children.6 Our aim was to ascertain whether or not dietary supplementation with vitamin D in infancy could reduce the risk of type 1 diabetes.