Final answer:
Soft tissue calcification is a common sign of vitamin D toxicity, which occurs when there's excessive vitamin D leading to elevated blood calcium levels, unlike vitamin D deficiency that results in rickets or osteomalacia.
Step-by-step explanation:
Among the signs of vitamin D toxicity, soft tissue calcification is a common symptom. Unlike vitamin D deficiency which can lead to conditions such as rickets (characterized by bowed legs) and osteomalacia (soft bones prone to fractures), vitamin D excess can result in elevated calcium levels in the blood. This hypercalcemia can in turn cause calcification of soft tissues and organs.
The synthesis of vitamin D in the human body involves the conversion of cholesterol into cholecalciferol upon exposure to UV radiation and its further processing in the liver and kidneys. Vitamin D is crucial for the normal absorption of calcium and phosphorus, which are required for healthy bones. Thus, when vitamin D levels are excessively high, it can lead to the mobilization of too much calcium, potentially leading to soft tissue calcification.