Last month, the Information Center Nutritional Supplements & Health (IVG) announced that vitamin D has been selected as the food supplement of the year 2021. Every year, this agency does research into the use of and trends in nutritional supplements. This year, no less than 70% of the 2,500 respondents indicated that they used a vitamin D supplement. In particular, the role that vitamin D plays in promoting resistance was an important reason for the selection. Vitamin D Sun vitamin, Vitamin D is produced in the skin under the influence of sunlight. But what if the sun - for example in winter ...