Lassens is a natural food and vitamins chain store based in Ventura, California. It is also my preferred store to shop natural food and supplements when I am visiting Los Angeles. I always find that it has the best variety of speciality and raw foods and organic health foods. They also seem to focus a lot on vegan. Their vegan chocolates are to die for! They also have a small deli section where you can order grilled or fried foods and sandwiches and health smoothies. There is also a section of alternative toiletries and home needs items. The only downside is that I find it much more expensive than other stores like Whole Foods and Trader Joe's, for eg. the same packet of organic muesli from the same company is a couple of dollars more expensive here than at other supermarkets.
Do keep in mind that parking at Lassens is quite limited and during weekends or rush hour, it is usually difficult to find a spot. Sometimes, I drive there with a friend who drops me and then drives around the block or parks somewhere nearby till I finish shopping.