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Vitamin A

Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, and several provitamin A carotenoids (most notably beta-carotene). Vitamin A has multiple functions: it is important for growth and development, for the maintenance of the immune system, and for good vision. Vitamin A is needed by the retina of the eye in the form of retinal, which combines with protein opsin to form rhodopsin, the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision. Vitamin A also functions in a very different role as retinoic acid (an irreversibly oxidized form of retinol), which is an important hormone-like growth factor for epithelial and other cells.

Metrics Summary

Total Publications
Lifetime
18,867
Prior Five Years
1,460
Total Citations
Lifetime
280,714
Prior Five Years
10,651
Total Scholars
Lifetime
23,256
Prior Five Years
13,654

Institutional Rankings

Global (Worldwide)
Academic Institutions
Lifetime
Academic Institutions
Prior Five Years
Non-academic Institutions
Lifetime
#1
United States
#1
United States
#1
#2
United States
#2
China
#2
Switzerland
#3
United States
#3
Israel
#3
United States
#4
United States
#4
United States
#4
United States
#5
Sweden
#5
United States
#6
United States
#6
United States
#7
United States
#7
Pakistan
#8
United States
#8
United States
#9
United States
#9
United States
#10
United States
#10
United Kingdom
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National Institutional Rankings

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Scholars based on Disciplines

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Scholars based on Fields

Highly Ranked Scholars™

Lifetime
Prior Five Years

Highly Cited Publications

Lifetime