Necessary for a balanced diet in human hands is the regular (but not excessive!) enrichment of the diet with vitamins and minerals. A well-tried combined preparation is "Korvimin ZVT", a powder which can be sprikled once a day on the crickets.
To support physiological intestinal flora, especially for non-specific digestive problems or after antibiotic treatment, an addition of "Bene-Bac-Pulver", is recommended every 1 or 2 days, sprinkled on the cricket meal.
The homeopathic preparation "Viruvetsan" has proved to be a valuable drinking water additive. It supports the body's own immune defences. To a small bowl of water (about 40 ml), about 8-10 drops of "Viruvetsan" are added.
A sufficient supply of vitamins of the B group is generally not possible using normal feeding and additives. This can lead to a life-threatening vitamin B deficiency. Hand raised swifts should therefore receive from a vet a sub-cutaneous injection of vitamin B complexes every 10-12 days.
There is no sense in providing incorrect feeding through excessively rich addition of vitamins and minerals. If they suddenly got as many chocolates, it would be just as difficult to maintain their health.