Raisins are merely dried grapes, and since grapes are Paleo, so are raisins. They don’t have quite as much vitamin C as grapes, but they are a rich source of iron, magnesium, phosphorous, potassium, and various B vitamins, most notably B6, thiamine and riboflavin.
Paleo and Sugar
Raisins are extremely high in carbohydrates though, and because they are dried, they don’t have the water content of grapes, which can help prevent overeating. Raisins can contain as much as 72% sugar by weight, most of which is fructose and glucose. Most of us eating a Paleo diet should be fine eating a handful of raisins here and there, but everyone is different. Some people are more sensitive to carbohydrates and find that they feel better when they limit them. Others need a slightly higher carb content in order to feel their best.
If you want to make your own raisins, Mark Sisson has a number of great tips to do just that.