Vinny66 - would you be so kind to publish here where in ecuador you can buy all kinds of vitamins. I live in Loja, but get to Cuenca on occasion (visit the doctor there) and sometimes get up to Quito (a 12-hour bus ride from Loja).
In Loja, there are very few places that sell vitamins you find in the US, and those sold are often small quantities and expensive (eg. vitamin C). In other cases, you might be able to buy a brand name, Centrum (sp?) for example, but may be getting a knock-off that is unreliable (a huge problem in Ecuador for all brand names). Shipping from the U.S. is problematic because of the cost of shipping and because many places do not ship to Ecuador (Amazon, for example). iHerb does. A few bottles of vitamins through iHerb is about $22 shipping - use DHL. Shipping time is usually about two weeks.
The best place to find american items is Supermaxi (or Megamaxi in larger cities), which is a U.S. style grocery store. It's pretty nice but variety is very limited. Lately, the Ecuadorian government has been pushing stores to feature Ecuadorian products and many of the American products are being pushed out. But keep in mind that Ecuador does not use GMO or artificial ingredients, so the ketchup from Ecuador, for example, will not contain high fructose corn syrup. The american version (Heintz) will. That's a good thing. Food here is very high quality. Vitamins in Supermaxi are mostly Centrum, Calcium, vitamin C, etc. But no magnesium (go figure). I have not found any magnesium here.
Prescription medicine is another matter. The pharmacies here do not use prescription. Just walk up to the counter and let them know what you need. The pharmacies are typically very small and stock is limited. But, describe what you need and they can usually offer something. However, they definitely do not carry the less common medicines. I take Fexafenadin (Allegra) substitutes do not work for me. My doctor in Cuenca looked it up and confirmed that is is not available in Ecuador. I bring a years supply with me each time I visit the U.S. But, some things do not have a year's shelf life. For example, my Omega-3 vitamins don't last more than 6 months. If you take prescriptions, you want to check out availability and appropriate substitutes.
In answer to another question, I have not seen Amway products here, but that does not mean that there are no Americans providing them. You'll just have to check out the American communities here. Loja doesn't have many non-ecuadorians.
And another: losartan (high blood pressure med) is available at about $0.80 per pill. Oddly, you can buy one pill at a time; they have no problem cutting one pill from the bubble pack. So, if you have a headache, just pop into the farmacia (they are everywhere) and buy one Umbral (Acetaminofin). It is like that here. If you ruin out of phone minutes, just pop into a store and get a few dollars recharge.
An observation: People here are exceptionally nice, but keep in mind that when you walk out of a store, don't come back and try to return something. That is just not common. Nor is going anywhere and raising hell about anything. Anger is not common and is definitely not acceptable. It is one of the things I love about Ecuador. Things can usually be settled with friendly discussion. If not, then one just has to accept it.
One final point, if you do ship to Ecuador, it is best to keep the package at 5 lbs (2 kilos) or less. I have not personally had an issue, but some have told me about problems with larger packages. Mail is pretty reliable but I have to go to the post office to inquire if a package has arrived.