Vitamin D: Sources and Functions

What is the active molecule of vitamin D?

Calcitriol

What is the endogenous vitamin precursor in humans?

7-Dehydrocholesterol

What is the function of vitamin D in the body?

Maintenance of plasma calcium levels

What is the recommended dietary allowance (RDA) of vitamin D for individuals over 70 years old?

20 µg/day Signup and view all the answers

What is the consequence of vitamin D deficiency in children?

Rickets Signup and view all the answers

What is a potential consequence of vitamin D toxicity?

Hypercalcemia Signup and view all the answers

What is the result of thiamine deficiency on cellular functions?

Decreased production of ATP and impaired cellular functions Signup and view all the answers

What is the characteristic of infantile beriberi?

Seen in nursing infants whose mothers are deficient in thiamine Signup and view all the answers

What are the two biologically active forms of riboflavin?

FMN and FAD Signup and view all the answers

What is the function of riboflavin in the body?

Metabolism reactions of amino acids and carbohydrates Signup and view all the answers

What is the function of niacin in the body?

Normal embryo development and metabolism reactions Signup and view all the answers

What are the biologically active forms of niacin?

NAD+ and NADP+ Signup and view all the answers

What is the primary effect of niacin on liver function?

Decreases liver triacylglycerol synthesis Signup and view all the answers

What is the term for the disease caused by niacin deficiency?

Pellagra Signup and view all the answers

What is the active form of folic acid?

Tetrahydrofolate (THF) Signup and view all the answers

What is the primary function of tetrahydrofolate (THF)?

Carrier of one carbon fragments Signup and view all the answers

What is a common cause of folic acid deficiency?

Insufficient dietary intake Signup and view all the answers

What is the characteristic of red blood cells in folic acid deficiency?

Macrocytic anemia Signup and view all the answers

What is the consequence of folic acid deficiency during pregnancy?

Neural tube defects Signup and view all the answers

What is the function of vitamin B12 in the production of red blood cells?

Remethylation of homocysteine to methionine Signup and view all the answers

What is the cause of vitamin B12 deficiency in pernicious anemia?

Deficiency of intrinsic factor Signup and view all the answers

What is the clinical manifestation of vitamin B12 deficiency?

Megaloblastic anemia Signup and view all the answers

How is vitamin B12 deficiency diagnosed?

By measuring the level of methylmalonic acid in blood Signup and view all the answers

How is vitamin B12 deficiency treated?

Intramuscular injection of vitamin B12 Signup and view all the answers

What is the term used to describe pyridoxine, pyridoxal, and pyridoxamine?

Vitamin B6 Signup and view all the answers

Where is pyridoxine typically found?

In plants Signup and view all the answers

What is the biologically active coenzyme formed from pyridoxine, pyridoxal, and pyridoxamine?

Pyridoxal phosphate (PLP) Signup and view all the answers

What is a potential cause of vitamin B6 deficiency?

Taking oral contraceptives Signup and view all the answers

What is a clinical indication for pyridoxine supplementation?

Treatment of isoniazid-induced vitamin B6 deficiency Signup and view all the answers

What is a characteristic of biotin?

It is widely distributed in food Signup and view all the answers