vitamin D
Definition
Vitamin D is a fat-soluble vitamin that is essential for the absorption of calcium and phosphorus. It is also involved in the function of the immune system, nervous system, and muscles.
There are two main forms of vitamin D: cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2). Vitamin D3 is produced in the skin when it is exposed to sunlight. Vitamin D2 is found in some foods, such as fortified milk and cereals.
The recommended daily intake of vitamin D for adults is 15 micrograms (mcg). Children need less vitamin D, depending on their age.
People who are at risk of vitamin D deficiency include those who live in northern latitudes, those who have dark skin, and those who are overweight or obese. People with certain medical conditions, such as Crohn's disease or celiac disease, may also be at risk of vitamin D deficiency.
Vitamin D deficiency can lead to a number of health problems, including rickets (a bone disease in children), osteomalacia (a bone disease in adults), and osteoporosis (a condition that makes bones weak and brittle).
Vitamin D can be taken as a supplement. However, it is important to talk to your doctor before taking any supplements, as too much vitamin D can be harmful.
How can the word be used?
The doctor prescribed a vitamin D supplement.
Different forms of the word
Noun:
a fat-soluble vitamin that is essential for the absorption of calcium and phosphorus, and for the maintenance of strong bones and teeth.
Adjective: of or relating to vitamin D.
Etymology
The word "vitamin D" is a combination of the word "vitamin" and the letter "D".
The word "vitamin" comes from the Latin word "vita", which means "life".
The letter "D" is used because vitamin D was originally thought to be a cure for rickets, a disease that causes soft bones.
The first recorded use of the word "vitamin D" was in 1922.
Question
What foods contain vitamin D?
AQA Science Exam Question and Answer
Question:
Explain the role of vitamin D in the human body and the potential consequences of its deficiency. Provide an example of a natural source of vitamin D and how it contributes to maintaining bone health.
Answer:
Vitamin D plays a vital role in maintaining overall health, primarily by regulating calcium and phosphorus absorption in the intestines. This function is crucial for bone health, as it ensures proper mineralization and strength. Additionally, vitamin D contributes to immune system function, cell growth, and reduction of inflammation.
A deficiency in vitamin D can lead to health issues such as weakened bones, known as rickets in children and osteomalacia in adults. Inadequate vitamin D levels may also increase the risk of bone fractures and impact overall immune system efficiency.
An example of a natural source of vitamin D is sunlight. When the skin is exposed to ultraviolet B (UVB) rays from the sun, a precursor molecule in the skin is converted into active vitamin D. This process highlights the significance of sunlight exposure for maintaining optimal vitamin D levels.
Vitamin D's contribution to bone health is exemplified by its role in calcium absorption. Adequate vitamin D ensures that calcium is effectively absorbed from the digestive tract into the bloodstream, subsequently facilitating its incorporation into bones and teeth.