Final answer:
Rickets is a condition in children caused by a deficiency in vitamin D, resulting in soft, deformed, and fragile bones, along with increased levels of blood calcium and phosphate ions.
Step-by-step explanation:
The condition characterized by soft deformed, fragile bones and increased levels of blood calcium and phosphate ions in children is rickets. Rickets is a disorder caused by a deficiency in vitamin D, leading to inadequate calcification of the bones. Bones that do not have enough calcium can lead to deformities, such as bowing of the leg bones, and an increased risk of fractures. Additionally, rickets is associated with serum phosphate levels of 1 to 2 mg/100 ml and a reduced product of calcium and phosphorus in the serum. It's vital to distinguish rickets from other conditions like osteoporosis and hyperparathyroidism, which occur in older adults or due to parathyroid gland abnormalities, respectively, and involve different mechanisms of bone density reduction or changes in serum calcium and phosphate levels.