This is the 501st most frequent Icelandic word.
a
The Icelandic word "á" means "on," "river," or "has" depending on context.
The word "a" serves here as a qualifier to the noun "vítamín" indicating one of a kind.
Ég vil fá a vítamín.
I want a vitamin.
In this context, "a" acts as a preposition that modifies the noun following it.
Það er alltaf fallegt að sjá a skinið.
It is always beautiful to see the skin.
Here, "a" functions as a preposition linking the verb to the object.