JN: Welcome!  The world looks quite different after you've read TGC, doesn't it?  Did you pick it up at one of the Sacramento signings last weekend?

You are absolutely correct -- we get plenty of all nutrients, IF we eat what humans have eaten for millions of years.  (I believe this is the article you're referring to.)

Unfortunately, what you refer to as "a normal diet" isn't practiced by the majority of Americans -- who either eat pure junk food, or are bamboozled by government propaganda like the "food pyramid" into avoiding the very foods that provide us with needed nutrients, and into eating huge amounts of fat and diabetes-promoting grains and starches with little nutritive value.  

There's a reason that all store-bought grain products, like flour and breakfast cereal, are "fortified" with vitamins and minerals: not only do they have almost none to begin with, they contain anti-nutrients like phytate, which binds to phosphorous, iron, zinc, calcium, and magnesium, preventing your body from absorbing them.  Phytate also binds niacin, which causes pellagra, a well-known problem in developing countries with high-grain, low-meat diets -- and in the USA, until we started "fortifying" grains with the vitamins they bind or don't contain. 

"In the early 1900s, pellagra reached epidemic proportions in the American South. There were 1,306 reported pellagra deaths in South Carolina during the first ten months of 1915; 100,000 Southerners were affected in 1916."

http://en.wikipedia.org/wiki/Pellagra

Then there are lectins, trypsin inhibitors, phytoestrogens…all anti-nutrients we ingest in large quantities as part of the government-recommended "food pyramid", which is full of foods that didn't exist until a few thousand years ago…or, in the case of 'vegetable oil' (actually grain oil), less than 100 years ago!

Let's look at the vitamin D 'problem'.  The best natural sources of vitamin D are meat, eggs, and fatty fish…exactly the foods that the 'food pyramid' says not to eat, and exactly the foods that provided the overwhelming majority of calories in the human diet for millions of years!  No wonder people are deficient in vitamin D!  And no wonder we need to 'fortify' grains with a laundry list of vitamins and minerals…we're telling people to avoid the very foods that naturally contain them, and that we've been eating since we were little 90-pound savanna apes.

In short, if we eat what's popularly known as the 'paleo' diet, we don't need an expensive cabinet full of supplements in order to maintain optimum health.  The primary calorie and nutrition source is meat, including fat, liver, and other organ meats; fish; vegetables; fruit; occasional root starches (potatoes, esp. sweet potatoes); and occasional nuts.

Thanks for the comments: feel free to pull up a log and stay a while, as I'll be exploring a lot more 'paleo' topics in the future.

JS

A further note on Vitamin D:

The primary source of Vitamin D is sunlight: our body synthesizes it in response to sun exposure. Therefore, the secondary reason for Vitamin D deficiency is our sun-phobia: not only do we spend most of our time indoors, we are told that UV rays will inevitably give us cancer if they strike our skin for more than a couple minutes.

The trouble is that UV rays hitting our skin is what makes Vitamin D.  So by continually slathering ourselves in sunscreen and yielding to sun paranoia, we've caused ourselves to become deficient in this important vitamin.

Also keep in mind that, despite the continual barrage of propaganda, there is no correlation between sunscreen use and skin cancer:

http://www.ncbi.nlm.nih.gov/pubmed/11966729

"...Compared with the highest quartile, being in the lowest quartile (25[OH]D levels <17.8 ng/mL) was associated with a 26% increased rate of all-cause mortality"