What is the recommended daily allowance (RDA) of vitamin D for adults?

The recommended daily allowance (RDA) of vitamin D for adults is 600 IU. This guideline reflects the amount needed to maintain bone health and overall physiological functions that rely on vitamin D, such as calcium absorption. Adequate levels of vitamin D are crucial in preventing deficiencies that can lead to issues such as osteomalacia in adults and rickets in children.

Research indicates that while some individuals may require more vitamin D, especially older adults or those with limited sun exposure, the 600 IU RDA serves as a baseline for most healthy adults. It's important to consider varying factors that may affect individual needs, such as age, geographic location, and certain health conditions that might impact vitamin D metabolism.

While higher levels, like 800 IU, may be recommended for older adults to optimize bone density and minimize fracture risk, the standard RDA established by health authorities remains at 600 IU for the general adult population.