Doppelherz Vitamins for Diabetics. When the daily diet is unbalanced, the intake of essential nutrients is often marginal and below optimum. This is especially true when a metabolic disorder exists or when a restricted diet has to be followed. Vitamin and mineral deficiencies are quite common in diabetics and people who are on a diabetic diet. Doppelherz Vitamins for Diabetics has been specially developed for them to cover their nutritional needs. Doppelherz Vitamins for Diabetics. When the daily diet is unbalanced, the intake of essential nutrients is often marginal and below optimum. This is especially true when a metabolic disorder exists or when a restricted diet has to be followed. Vitamin and mineral deficiencies are quite common in diabetics and people who are on a diabetic diet. Doppelherz Vitamins for Diabetics has been specially developed for them to cover their nutritional needs.