Hi B.,
Finding an adult chewable is a challenge. I would agree that Shaklee's products have the most clinical proof of their purity, absorbability and results. What you want to look for is which products are as close to how things grow in nature as possible. Some of the others recommended here have been proven to have lead contamination. Others are extremely unbalanced which means you're getting way too much of one thing and not nearly enough of another. It is not enough to have one person's testimonial of what a product did for them. Instead, consider the company's history and integrity for using only pure and clean raw ingredients, guaranteeing their's absorbable, and that they are what your body needs where they're needed. In fact, you'd be better off using NO supplements than using brands other than Shaklee - and there's proof. The University of California did a study with people who took no vitamins, people who took various other brands, and people who took Shaklee. The results showed that in 5 areas of blook work, people who took no vitamins, had better blood scores than those who took other brands. You can see the numbers here if you'd like: http://changealife.blogspot.com. Don't take chances with your health. It is the most valuable thing you have.