What disease in adults means ‘soft bones’ that usually develops due to a deficiency of vitamin D (often from not getting enough sunlight), or less often, digestive or kidney disease?

Osteomalacia

The correct answer is Option (3) - Osteomalacia

The correct term for the disease in adults that means 'soft bones' due to a deficiency of vitamin D is: Osteomalacia

• Explanation:
• Osteomalacia is a condition characterized by softening of the bones, often caused by a deficiency of vitamin D. Vitamin D is essential for the proper absorption of calcium and phosphorus in the body, which are crucial for bone health. Inadequate exposure to sunlight, a lack of vitamin D in the diet, or issues with the absorption of vitamin D in the digestive tract can contribute to the development of osteomalacia.
• Osteoporosis and osteopenia are related conditions involving decreased bone density, but they are not specifically associated with the term 'soft bones'. Osteomyelitis, on the other hand, is an infection of the bone and not directly related to vitamin D deficiency.