More Vitamin D studies than total of Omega-3 and Vitamins A, C, E, K – as of 2021
In PubMed title through 2021
| Vitamin D | 2979 |
| Vitamin A | 261 |
| Vitamin C | 452 |
| Vitamin E | 361 |
| Vitamin K | 385 |
| Omega-3 | 994 |
Similar situation in 2015
from our video Does Less Sun mean More Disease