I wanted to clarify and add a few things about previous posts.
First, Creasy explains the importance of attracting good insects, including pollinators. According to Creasy, having flowers growing near your vegetables is not only ornamental, but it can help attract beneficial bugs and pollinators, especially if the flowers are appealing to bees.
Creasy also provides information about related plants and explains how these plants can cross pollinate, perhaps giving you hybrid varieties that are unappealing and making seed saving a wasted effort. She also points out that it’s important to take this into mind when planning beds and rotating crops, so that you aren’t letting pests and soil pathogens establish themselves too firmly. She also lists some good cover crops to use in between edible crop rotations.
I’d also like to clarify my stance regarding vitamins and nutritional supplements. I’m not opposed to them across the board. I think that the added B vitamins in cereals, vitamin D in milk, and iodine in salt are valuable correctives to serious nutrient deficiencies whose absence we in the US now take for granted. (The lack of iodine in salt leads to Cretinism in parts of the developing world.) I just don’t feel like taking even more supplements is useful in the absence of a specific deficiency like iron-related anemia, vitamin D deficiency (which sometimes occurs in exclusively breast fed babies, especially ones with dark skin), etc.