Final answer:
The tolerable upper limit for vitamin K has not been established, as the body can handle excess amounts quite well. Adult men need 120 mcg and women need 90 mcg of vitamin K per day through diet or intestinal bacterial synthesis. Vitamin intake varies by sex, with men requiring more vitamin K, while women need additional iron.
Step-by-step explanation:
The tolerable upper limit (UL) for vitamin K has not been established due to its low potential for toxicity and because the body eliminates excess amounts. However, very large doses of vitamin K can be toxic, although such cases are rare. The average diet typically includes an adequate amount of vitamin K, since it is synthesized by intestinal bacteria. In most healthy individuals, deficiency symptoms are not common, except for newborn infants breastfeeding from mothers with low vitamin K diets.
For adults, the recommended intake of vitamin K is 120 micrograms (mcg) per day for men and 90 mcg per day for women. This can be obtained through consumption of green leafy vegetables like spinach and cabbage, as well as some other foods like cauliflower, soybeans, and wheat germ. Additionally, a small amount of vitamin K2 is produced by bacteria in the human intestine.
Men typically require more vitamins C and K compared to women, who need extra iron due to menstruation. This indicates the difference in micronutrient needs between the sexes, particularly for active young adults who might require additional minerals and vitamins.