Serpent (symbolism) The serpent, or snake, is one of the oldest and most widespread mythological symbols. The word is derived from Latin serpens, a crawling animal or snake. Snakes have been associated with some of the oldest rituals known to humankind and represent dual expression of good and evil.
1 Osteoporosis, a condition characterized by reduced bone mineral density and increased bone fragility.  Rickets, a childhood disease characterized by impeded growth and deformity of the long bones. The earliest sign of subclinical vitamin D deficiency is craniotabes, abnormal softening or thinning of the skull.
Vitamin D deficiency has been linked with rickets, cancer, cardiovascular disease, severe asthma in children and cognitive impairment in older adults. Causes include not ingesting enough of the vitamin over time, having limited exposure to sunlight, having dark skin, and obesity. Symptoms include bone pain and muscle weakness.