Low 25 hydroxyvitamin D has the potential to produce the following hazards: First, it leads to severe osteoporosis. Low levels of this hormone can lead to impairment of calcium absorption in the gastrointestinal tract. This can lead to a decrease in the amount of bone in the body, which in turn can lead to osteoporosis. Secondly, it leads to a decrease in blood calcium level of patients. Low levels of these hormones reduce the absorption of calcium in the body, which in turn lowers blood calcium levels. In this case, the patient may have cramps, convulsions, peripheral pain or heart arrhythmia. Thirdly, the growth and development of the patient is hindered. If the patient is in adolescence, the lowered hormone level will cause the patient’s growth and development to slow down, and may produce a series of deformities such as chicken chest, funnel chest, rib beads, etc.