The majority of b-vitamin deficiencies in today's world can be associated with

The majority of B-vitamin deficiencies in today's world can be associated with consuming alcohol and cooking  

Explanation:

Vitamin B is most essential to be consumed for the metabolic processes and they are very delicate. Over cooking easily takes away the Vitamin-B from the food. Alcohol when consumed takes away all the vitamin-B from the kidney.

Hence majority of B-vitamin deficiency is caused by consuming alcohol and over cooking. It is important to have a food that is rich in vitamins and normally Vitamin-B is used for cell health and keep our body energetic.