Natural vitamin B1 sources are brewer's yeast, whole grains, blackstrap molasses, brown rice, organ meats, egg yolk Natural vitamin B2 sources are brewer's yeast, whole grains, legumes, nuts, organ meats, blackstrap molasses
Natural vitamin B3 sources are lean meats, poultry & fish, brewer's yeast, peanuts, milk, rice bran, potatoes Natural vitamin B4 sources are egg yolks, organ meats, brewer's yeast, wheat germ.
It is no longer news that the so called natural products are more expensive than their synthetic counterparts. While the price difference can be justified by the means they are prepared, unless proof is given that one is more effective than the other then there's no cause for a debate. The debate over which is better may never be over since a person will always prefer one thing over the other.
But regardless of the source and the means of producing these supplements, what really is important is the actual amount of vitamins present there.
Some natural ones have additional ingredients which lessen there intended effect while there are synthetic ones that are overstuffed with a lot of vitamins which in effect lessens their effectiveness.