The shift from low to high calcium is often caused by over-correction with calcium or vitamin D supplements (like calcitriol) used for your childhood condition, or changes in parathyroid gland function. This calcium imbalance can weaken bones, potentially causing stress fractures or joint pain in your feet. Please consult your doctor promptly to check your parathyroid hormone (PTH) levels and get a foot X-ray. Do not self-medicate. Your doctor may adjust your current supplements, advise increased hydration, or prescribe medications like bisphosphonates (e.g., alendronate) to protect your bones. This is a highly manageable issue once your dosage is correctly adjusted.