Supplements & dusting
Feeder insects alone are nutritionally incomplete. Calcium supplementation is non-negotiable — Metabolic Bone Disease (MBD) is among the most common and preventable health issues in captive African fat-tailed geckos.
The core supplements
Primary defence against Metabolic Bone Disease. Dust feeders lightly just before offering. Choose a product with a sensible D3 level and do not stack it with other D3 sources without checking the totals. If you run a UVB lamp, use D3-containing powder less often — your vet or the product's guidance can give the exact reduction.
Many geckos regulate their own calcium intake by licking from a small dish. Keeping one in the enclosure means calcium is always available and reduces the risk of over-supplementing D3 through dusting alone. Replace it if it gets damp or fouled — humid-hide setups make this more likely for a fat-tail than for a drier-kept gecko.
Covers vitamins A, B complex and E that feeder insects lack even when gut-loaded. Hypervitaminosis A is a documented risk in reptiles, so do not exceed weekly use and check labels when combining products. Pick a multivitamin with beta-carotene (a vitamin A precursor) rather than pre-formed vitamin A where you can.
Fat-tails are nocturnal or crepuscular and get little sun in the wild, but a captive gecko under low-output UVB (about Ferguson zone 1–2 strength, on for 10–12 hours a day) can synthesise some D3 through its skin. If you provide UVB, lean on plain calcium more often and use D3 powder less frequently. Ask a reptile vet for exact figures for your lamp and setup.