Small specialist primates such as marmosets and tamarins (callitrichids) have special, particular needs. Primates are omnivores; they eat invertebrates, fruits, vegetables, gums (rich in natural soluble fibre), small birds, in fact they will eat almost anything! Selective feeding in captivity has caused many nutritional problems, and so the general recommendation is to use a commercial diet as a major part of the food.
All primates need vitamin C from fresh fruit and veg, but New World (a term used to refer mainly to America) primates have a special need for vitamin D3, and some of this need can be met by using proper lighting to incorporate good UV-B sources. During the summer especially, allowing exposure to natural sunlight should be sufficient.
At Vetark we have two major sources of vitamin D3, the first is Nutrobal which is a full vitamin & mineral supplement containing plenty of calcium, plus vitamin C. This may be more calcium than is needed if the animals are receiving a good diet. It is also very useful for dusting mealworms or crickets when they form part of the balanced diet. As an alternative, Zolcal D is a simpler source of just vitamin D3 and calcium, and its liquid formula means it is quite easily disguised in porridge and other similar foods.
A third route has also been used is giving ACE-High to animals receiving a commercial diet and perhaps less fruit and vegetables than ideal / recommended. ACE-High still provides some D3 and calcium (these will be in the commercial diet as well so high levels in supplements aren't necessary) but it provides extra vitamins A, C and E - as the name states. This route has been used very successfully, particularly on many small callitrichids.
Callitrichids in particular generate a powerful odour. Ark-Klens, our disinfectant/cleanser, is excellent for removing this. The musky odour is associated with oils and fatty acids within the urine. Ark-Klens is a powerful sanitiser and de-odouriser without trying to mask odours with an essence of pine woods or the seaside, cutting through the smell molecules and removes them from surfaces.