What is the recommended daily allowance (RDA) of Vitamin D for adults with limited sun exposure?

The recommended daily allowance (RDA) of Vitamin D for adults with limited sun exposure is indeed best represented by the range of 1,500 to 2,000 IU. This higher intake is crucial, especially for individuals who do not receive sufficient sunlight, as the skin synthesizes Vitamin D when exposed to UV rays. Insufficient sun exposure can lead to lower Vitamin D levels and potentially result in deficiencies, which can affect bone health and immune function.

The alternative options do not cover the needs of adults who have limited sun exposure adequately. Although 600 IU is the established RDA for adults in general healthy circumstances, it may not be sufficient for those at risk of deficiency. Similarly, while 1,000 IU can also be beneficial, it may not provide enough of a buffer for individuals whose sun exposure is very restricted. The highest option, 2,500 IU, exceeds the generally recommended limit and is typically not necessary for the average adult but may be considered for therapeutic scenarios under medical guidance. Hence, the range of 1,500 to 2,000 IU is recommended for optimal health and to prevent deficiency in these individuals.