What are the symptoms of excessive secretion of parathyroid hormone?

Many symptoms: Parathyroid hormone is responsible for regulating calcium level in blood. The most common cause of hyperparathyroidism is a growth on your parathyroid gland causing overproduction of this hormone. If high, it will raise calcium level in your blood causing osteoporosis, kidney stones, kidney problems, bone pain, constipation, abdominal pain, psychological problems...

Depends: If vit d is normal then excess PTH will elevate the blood calcium to abnormal which can affect kidney, bones, abdomen, and brain if vit d is low then excess PTH is secreted to keep the blood calcium normal.