The Nutrient Reference Value (NRV) for Vitamin D can vary depending on the country and the specific guidelines followed. However, as of my knowledge cutoff in September 2021, the NRV for Vitamin D is generally recommended to be around 5 micrograms (mcg) or 200 International Units (IU) per day for adults.
It's important to note that the NRV may vary for different age groups and special populations, such as infants, children, pregnant women, or individuals with certain medical conditions. It's always best to consult the specific guidelines provided by your local health authority or a healthcare professional for the most accurate and up-to-date information on recommended daily intake of Vitamin D.