It’s essential for fighting infections and cancer and for a healthy pregnancy. A shirtless white person gets around 15,000 IU’s from 30 minutes in the sun. I take around 15,000 per day unless I’m feeling ill, then I take 30K. To the extent that a black person relies on sunshine, he’ll need more exposure than a white person.
Needless to say the FDA’s RDA is clear evidence of high-level corruption. Also needless to say this corruption is systemic in the whole medical field and manifests in everything from the “food pyramid” to vaccines. If you want to have a long life, find out what our ancestors did for 1000’s of years before the industrial revolution. That’s what your system is optimized for.