American Board of Orthodontics (ABO) Practice Exam

Vitamin D deficiency in adults primarily leads to osteomalacia, which is characterized by the softening of bones due to inadequate mineralization. Unlike rickets, which occurs in children, osteomalacia affects adults and is a direct result of insufficient levels of vitamin D, calcium, or phosphate. In this condition, despite normal bone matrix formation, there is a failure to mineralize the new bone properly, resulting in weakened bones that can lead to bone pain and increased risk of fractures.

While other conditions like osteoporosis can also be influenced by vitamin D deficiency, they primarily relate to bone density loss rather than the quality of the bone structure as seen in osteomalacia. Osteoporosis involves a reduction in bone mass and density, often manifesting later and tending to be more associated with age and other factors, while osteomalacia directly results from a lack of vitamin D and its immediate effect on bone mineralization. Hyperparathyroidism can occur as a consequence of prolonged vitamin D deficiency but is not the primary condition associated with it.