When fortifying milk with vitamin D, what is the minimum number of vitamin D units required per quart?

Fortifying milk with vitamin D is a public health measure aimed at preventing deficiencies in the population, particularly among children and those at risk of osteoporosis. The minimum requirement for fortification, which helps maintain adequate levels of vitamin D, is established based on dietary guidelines and health recommendations.

The correct choice of 400 units of vitamin D per quart is based on the understanding that this amount contributes effectively to the nutritional needs of individuals. This level helps in promoting bone health and facilitating calcium absorption, which is crucial for both the skeletal system and overall health. Studies and health authorities have established 400 IU (International Units) as a practical benchmark for ensuring that populations receive adequate vitamin D through common dietary sources like milk, which is commonly consumed.

While lower amounts may not be sufficient to meet the recommended dietary allowances for various segments of the population, 400 IU has been identified as effective at helping maintain optimal health standards and preventing deficiency-related diseases, thereby reinforcing its status as the minimum fortification requirement.