Exam 8: Vitamins Required for Calcified Structures

Which vitamin acts most like a hormone?

When rickets occurs,the alveolar bone is affected similar to other bones in the body.The trabeculae of the alveolar bone also weaken.

Calcitonin,a hormone secreted by the thyroid gland,helps regulate mineralization of bones and teeth.Without adequate levels of vitamin C,calcitonin cannot regulate blood calcium and phosphorus levels.

International units (IUs)are the designation used to measure and recommend vitamin A levels because it better represents the absorption rates in humans than retinol activity equivalent (REA).

Each is true of retinoic acid,except one.Which is the exception?

Antioxidants prevent cell membrane damage by free radicals that are produced by cells and tissue using free oxygen.Research conclusively documents that the antioxidant beta-carotene is effective in preventing cancer.

Each is true of vitamin K,except one.Which is the exception?

Each is true of vitamin D,except one.Which is the exception?

A restriction of dietary vitamin K can alter clotting factors because synthesis of vitamin K by intestinal flora supplies less than 10% of the body's requirement.

Rickets results in shortened bones because the epiphyses of bones form earlier than normal.

Each is true of xerophthalmia,except one.Which is the exception?

Each is a form of vitamin K,except one.Which is the exception?

In older patients,vitamin D deficiency frequently results in falls because this deficiency is associated with muscle weakness.

Each is true of water-soluble vitamins,except one.Which is the exception?

Alopecia,diplopia,and increased activity of osteoclasts are most associated with an excess of which vitamin?

Daily intake of water-soluble vitamins is important because although the body can store large amounts of these nutrients,they are better utilized when consumed daily.

During early tooth development,vitamin A deficiency leads to enamel hypoplasia and defective dentin formation.Because of its effect on soft tissues and bone,vitamin A contributes to normal spacing of teeth.

Vitamin A can be stored in the liver for at least:

Although vitamins are synthesized during metabolic processes,they also must be obtained through external sources because vitamins cannot be produced in adequate amounts to meet body needs.

Toxicity from excessive intake of vitamin A food sources is common and results in hypercarotenemia.This condition is initially manifested by yellowing of the skin on upper chest and inner forearms.