vitamin D

(redirected from vitamin D D2)
Also found in: Dictionary, Thesaurus, Encyclopedia.

vi·ta·min D

generic descriptor for all steroids exhibiting the biologic activity of ergocalciferol or cholecalciferol, the antirachitic vitamins popularly called the "sun-ray vitamins." They promote the proper use of calcium and phosphorus, thereby producing growth, together with proper bone and tooth formation, in young children; the sulfate, a water-soluble conjugate, is found in the aqueous phase of human milk; vitamin D1 is a 1:1 mixture of lumisterol and vitamin D2.

vitamin D

n.
A fat-soluble vitamin occurring in several forms, especially vitamin D2 or vitamin D3, required for normal growth of teeth and bones, and produced in general by ultraviolet irradiation of sterols found in milk, fish, and eggs.

vitamin D2

n.
A white crystalline compound, C28H44O, produced by ultraviolet irradiation of ergosterol. Also called calciferol, ergocalciferol.

vitamin D3

n.
A colorless crystalline compound, C27H44O, found in fish-liver oils, irradiated milk, and all irradiated animal foodstuffs. It has essentially the same biological activity as vitamin D2. Also called cholecalciferol.

vitamin D

A mixture of several forms of vitamin D: Vitamin D3 is synthesised in the skin upon exposure to ultraviolet light; in contrast, vitamin D2 is obtained only from the diet. Both vitamins D2 and D3 are metabolised to 25-hydroxy vitamin D in the liver, and then to the active 1,25 dihydroxy form in the kidney. Vitamin D has a major role in the intestinal absorption of calcium, bone calcium balance and renal excretion of calcium, and is measured as part of a workup for hypocalcaemia, hypercalcaemia and hypophosphataemia.
 
Toxicity
Infants given excess vitamin D may develop atherosclerosis, severe mental retardation, facial dysmorphia, kidney damage, recurrent infections, anorexia, failure to thrive, and may die; as with adults ingesting megadoses of vitramin D, the damage is caused by excess calcium absorption.

vi·ta·min D

(vī'tă-min)
Generic descriptor for all steroids exhibiting the biologic activity of ergocalciferol or cholecalciferol, the antirachitic vitamins. They promote the proper use of calcium and phosphorus, thereby favoring proper bone and tooth formation and maintenance in children.

vitamin D

a fat-soluble molecule found in fish liver oils, and also produced in the skin when subjected to ultraviolet rays from sunlight. The main function of the vitamin is to increase the utilization of calcium and phosphorus in bones and teeth. A deficiency results in RICKETS in children and osteomalacia (bone-softening) in adults, particularly women after several pregnancies.

vi·ta·min D

(vī'tă-min)
Generic descriptor for all steroids exhibiting biologic activity of ergocalciferol or cholecalciferol, the antirachitic vitamins popularly called "sun-ray vitamins." They promote the proper use of calcium and phosphorus, thereby producing growth, together with proper bone and tooth formation, in young children.

Patient discussion about vitamin D

Q. Recently I came to know after a test that I am vitamin D deficient so how much vitamin D should I take? I am 26 yrs old and I have fibromyalgia. Recently I came to know after a test that I am vitamin D deficient so how much vitamin D should I take?

A. what is a normal level of vitamin d for a 65 yr old woman?

Q. Should I give my baby girl vitamin D? I have a 4 month old baby girl. I have been reading that it is advised to give babies vitamin D. Is this true?

A. Yes, it is advised to give babies a vitamin D supplement. Vitamin D deficiency (not having enough) can be prevented by giving babies a daily supplement (drops) of vitamin D.
Babies need vitamin D for healthy growth and development. It helps them build strong, healthy bones and teeth.
Babies who don’t get enough vitamin D are at risk of getting rickets, a disease that affects the way bones grow and develop. Vitamin D can also help prevent certain illnesses in childhood or later in life.

Q. What food are rich with vitamin D? My son is 4 years old and the Doctor said he has vitamin D deficiency and advised me to give him a vitamin D supplement. I don't like the idea of giving him medicine, can't I just give him food which is rich with vitamin D and if so which foods are rich with vitamin D?

A. The best way to get vitamin D, the way that our bodies were designed to get the vast majority of our vitamin D, is from modest sun exposure. Going outside regularly will help your son to generate adequate amounts of vitamin D. Therefore, on top of the medicine the Doctor prescribed, have him go outside in the sun everyday for about 20 minutes. (Keep in mind that there is a concern of sunburn and increased risk of skin cancer with too much sun exposure, however.)

More discussions about vitamin D