A one-and-a-half-month-old baby is experiencing nape baldness and milk regurgitation, and someone suggested it might be due to calcium deficiency. The parents have already undergone a trace element test, which shows no calcium deficiency. What tests are needed if there is a suspicion of low blood calcium? Is there a test called alkaline phosphatase? Is this test the same as the calcium in trace elements?

The baby’s liver function tests have shown elevated alkaline phosphatase levels in all three tests, but other indicators are normal.

A child’s alkaline phosphatase level reaching 300u/L may be an early sign of calcium deficiency. Appropriate supplementation with vitamin D and calcium tablets can help restore normal levels.

Discuss the possible causes, related diseases, and recommended examination methods for a seven-year-old girl with elevated alkaline phosphatase levels.