Small specialist primates such as marmosets and tamarins (callitrichids) have special needs.
Primates are omnivores, they eat invertebrates, fruits, vegetables, gums (rich in natural soluble fibre), small birds etc etc ie. almost anything. Selective feeding in captivity has caused all sorts of nutritional based problems, and so the general recommendation is to use a commercial diet as 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. Some of this need can be met by using proper lighting, incorporating good UV-B sources. During the summer especially allowing exposure to natural sunlight should be sufficient.
Vetark have two major sources of vitamin D3, the first is Nutrobal which is a full vitamin & mineral supplement containing plenty of calcium and some vitamin C in addition to the high level of D3. This may be more calcium than is needed if the animals are receiving a good diet. It is very useful for dusting mealworms or crickets when they form part of the diet. As an alternative, Zolcal D is a simpler source of just D3 and calcium. Zolcal D is a liquid and so is quite easily disguised in porridge etc.
A third route has also been used, that of giving ACE-High to animals receiving a commercial diet and perhaps less greens etc than ideal, ACE-High still provides some D3, and some 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 - hence its name. This route has been used very successfully on many small callitrichids especially.
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. It 'cuts' through the smell molecules and removes them from surfaces.