Vitamin D Flashcards

Vitamin D

Group of five fat-soluble molecules; main animal form is vitamin D3 (cholecalciferol) that promotes calcium absorption for bones.

Cholecalciferol (Vitamin D3)

The main animal form of vitamin D produced in skin; converted in the liver/kidneys to the active form; promotes calcium absorption.

7-Dehydrocholesterol

A steroid in the skin that, when exposed to UVB radiation, is converted to cholecalciferol (vitamin D3).

UVB radiation

Sunlight component that triggers the conversion of 7-dehydrocholesterol to cholecalciferol in the skin.

Osteomalacia

Bone pain and weakness in adults caused by vitamin D deficiency.

Rickets

Softening of bone growth plates in children due to vitamin D deficiency, leading to bowed legs.

Calciterol (Calcitriol)

Active form of vitamin D produced after processing in the liver and kidneys; regulates calcium and phosphate and supports bone and nervous system function.

Vitamin D Binding Protein (DBP)

Protein that binds calciterol and transports it to organs where it acts.

Fortification

Policy of adding vitamin D to foods (e.g., milk, cereals) to prevent deficiencies like rickets.

Ergocalciferol (Vitamin D2)

Plant-derived form of vitamin D added to foods; debated regarding efficiency compared to D3.

Direct sunlight exposure

Five to fifteen minutes of direct sun exposure can provide the vitamin D3 you need.

Vitamin D toxicity

Excess vitamin D (often from supplements) raising calcium levels and causing symptoms such as nausea, arrhythmias, and disorientation.

Calcium supplements (described as D2 in notes)

Notes state calcium supplements are D2 rather than D3; reflects a debate about the relative efficacy of D2 vs D3.

Vitamin E

Antioxidant studied in smokers; daily supplementation linked to higher risk of death from lung cancer or heart disease.

Beta-carotene

Antioxidant studied in smokers; supplementation linked to higher death rates from lung cancer.