Best sources are: "carrots, carrot juice, turkey, pumpkin", and RDA is 3000ug
But in http://en.wikipedia.org/wiki/Vitamin_A
6500ug in 100gr of beef liver
835ug in 100gr of carrots
~50gr of liver - 65Kcal (http://nutritiondata.self.com/facts/beef-products/3468/2
350gr carrots - 180Kcal (http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2383/2
The conclusion that can be drawn from the newer research is that fruits and vegetables are not as useful for obtaining vitamin A as was thought; in other words, the IUs that these foods were reported to contain were worth much less than the same number of IUs of fat-dissolved oilsB2
Wikipedia is less helpful (no exact numbers), I found here: http://www.healthaliciousness.com/articles/foods-high-in-riboflavin-vitamin-B2.php
Liver: 4.6mg per 100g serving or 270% of the DV - ~50Kcal for 1 DV.
Next best food source listed (not supplement) is almonds: 1.01mg (60% DV) of vitamin B2 per 100 gram serving - 900Kcal (1 DV).B3
Liver: the most niacin (B3) with 16.7mg per 100g serving or ~100% of the DV - ~135Kcal for 1 DV.
Peanuts provide 14.9mg (75% DV) in a 100 gram serving - 630Kcal.B5
Liver 8.3mg per 100g serving or 83% of the DV - 160kcal
Bran of rice/wheat - 7.4mg (74% DV) per 100g serving - ~500Kcal (who eats just the bran???)
I can do more - but note that a few servings of beef liver/meat will deliver everything you need, this is why eating vegetable diet you have to have, and I guess this is the source of the recommendation to eat as much varied nutrition as you possibly can - you simply have to.
And it is also not as bio-available in vegetables, which make sense evolutionary.