Vitamin K is essential for the following body functions:
* clotting of blood
Sources of Vitamin K:
Vitamin K is widespread in food in small amount. The best sources are the skins of fruits and dark green leafy vegetables such as:
Dietary Reference Intake
| Life Stage Group | RDA/AI* µg / day | Upper Limit µg / day |
| Infants 0-6 months 7-12 months | 2* 2.5* | Not determinable Not determinable |
| Children 1-3 years 4-8 years | 30* 55* | Not determinable Not determinable |
| Males 9-13 years 14-18 years 19 – >70 years | 60* 75* 120* | Not determinable Not determinable Not determinable |
| Females 9-13 years 14-18 years 19 – >70 years | 60* 75* 90* | Not determinable Not determinable Not determinable |
| Pregnancy <19 years 19 – >50 years | 75* 90* | Not determinable Not determinable |
| Lactation <19 years 19 – >50 years | 75* 90* | Not determinable Not determinable |
RDA = Recommended Dietary Allowances
AI* = Adequate Intakes
UL = Upper Limit
µ = one millionth, 0.000001
Vitamin K Deficiency
Vitamin K deficiency in adults is extremely rare because vitamin K can be synthesized in the intestines.