Vitamin K is essential for the following body functions:
Vitamin K is widespread in food in small amount. The best sources are the skins of fruits and dark green leafy vegetables such as:
| 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 in adults is extremely rare because vitamin K can be synthesized in the intestines.