Newborns in the U.S. are given a vitamin K shot at birth because their intestines are not mature enough to produce this essential nutrient for blood clotting on their own.
In the United States, babies receive a shot containing vitamin K at birth because their intestines are not fully developed, which affects their ability to synthesize this essential vitamin. Vitamin K is critical for proper blood clotting and bone development. Unlike some other vitamins, vitamin K is not adequately provided through the mother's milk, especially if the mother's diet is low in vitamin K. Moreover, babies' intestines do not have the bacteria that help synthesize this vitamin internally.
It is important to differentiate vitamin K from other vitamins discussed. Vitamin D deficiency, for instance, can lead to rickets, a condition that affects bone development due to malabsorption of calcium. Vitamins such as vitamin C are water-soluble and not stored in the body, whereas vitamin K and other fat-soluble vitamins (A, D, E) are stored to some extent.
The vitamin administered to babies at birth in the U.S. to ensure proper blood clotting and prevent bleeding problems is vitamin K.