When it comes to macronutrients, vitamins and minerals, there are generally no meaningful differences between organic and non-organic produce. The available data point out only two exceptional cases: organic meat and cow’s milk.
Organic cow’s milk conclusively shows around 50% higher content of total omega-3 fatty acids than conventional milk. Data about organic meat are less consistent with regard to the size of the effect, but they still demonstrate a significantly higher content of omega-3 fatty acids in beef, lamb and pork as compared to their conventionally-bred counterparts.