More preformed A, no, but given regularly at the proper dosage, absolutely. In my opinion, juveniles should be lightly supplemented no less than twice monthly and even as often as once weekly, depending on a variety of factors. The product you use and appropriate amounts will be variable, according to the animal's age, gender, health, hydration, and the type of lighting, temps, other supplements, prey gutloads, prey types, and other variables specific to each animal.
My best advice is to keep the hydrated, VERY hydrated, find a low dose product and use it weekly to every other week and observe your animal. If edema is noted, cut back. If eye problems develop, lethargy, or stunting occurs and can be ruled out as being cause by other factors, try supplementing more often. Gravid females should be getting low, weekly doses.
I like to look at products geared to smaller animals, such as dart frogs, which have much smaller doses and use these as I feel is appropriate. This is my experience, other's may vary.