Raisin Bran has quite a bit of phosphorous? Does it have double the calcium to balance that out? Lots of people feed shrimp. Just make sure it's been cooked well. Mine love it.

Vitamin D is NOT Calcium -

1 ounce (28 gm) Bran Flakes has 15.7 mg calcium and 142 mg phosphorus for a ratio of 0.11:1 - these are a very high phosphorus food.

You might want to take label reading a step further and look at the NutritionData web page

www.nutritiondata.com/

you can search for foods and see exactly how much calcium and phosphorus are in a specific amount of food.

I have broken this data down even further - to 1 TBS portions (usual glider serving size for most fruits & veggies) on my web page. You can use the Diet Calculator or just print out the printable page which shows many fruits, veggies and glider diets in serving size (1 TBS) amounts for you to compare.

www.gliderkids.com/references.html

i feed the chicken and brown rice diet it is pretty good

According to the US National Library of Medicine National Institute of Health. . . . .

Vitamin D is one of the oldest hormones that have been made in the earliest life forms for over 750 million years. Phytoplankton, zooplankton, and most plants and animals that are exposed to sunlight have the capacity to make vitamin D. Vitamin D is critically important for the development, growth, and maintenance of a healthy skeleton from birth until death. The major function of vitamin D is to maintain calcium homeostasis. It accomplishes this by increasing the efficiency of the intestine to absorb dietary calcium. When there is inadequate calcium in the diet to satisfy the body's calcium requirement, vitamin D communicates to the osteoblasts that signal osteoclast precursors to mature and dissolve the calcium stored in the bone.(This is the reason I associate Vitamin D with Calcium.)

I feed plenty of freshly diced fruits and vegetables that have Calcium and Phosphorus. I feed a fair amount of Yogurt and my Sugar Gliders get plenty of cooked unsalted meats.
I am confident that though I may not feed my Sugar Gliders strictly according to everyone else I have HAPPY,HEALTHY,ENERGETIC,BOUNCY and MISCHEVIOUS little Sugar Gliders.