Does he have access to a UVB source? Even with lots of calcium they can still develop MBD without exposure to UVB light. Twichting and lumps, especially along or near the spine are signs of this.
Are you sure your temps are hot enough? And is their basking spot lit with a bright spot lamp? If temps are too low or if their isn't a bright light to stimulate sunlight they will not always process calcium correctly either. (there are reports of people who only heated their tanks with ceramic heaters instead of bulbs have beardies that come down with MBD symptoms) They should have access top a bright basking spot between 105-115degrees.
Regardless of the problem dont just wait for it to get better because it probably wont. A visit to a good reptle vet is in order.
Hope this helps! Good luck,
Mim
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0.1 Bearded dragon
0.1 mexican kingsnake
1.0.2 Leopard Gecko's
0.0.1 Rose Hair Tarantula
1.0 BTS
0.0.1 Reverse Okeetee Corn
0.1 Bullmastiff
4.1 Cats