I have a hard time believing all these chemically extracted vitamins are as good as when they come from actual food. Need vitamin D? Drink milk and get some sun. Need B12? Eat green veggies. Need vitamin C? Eat fruit. Need all of the above and more? Eat Kale.
Part of the problem of trying to get all your micronutrients solely from food is the seriously depleted state of much of our soil. Studies have shown that our soils used to be significantly more nutrient rich, so people would have to eat a great deal more of a natural food item to get the same amounts of vitamins, minerals, amino acids, etc. as in earlier decades.
Farming and husbandry practices have also changed. For example, the old grass fed style of raising cattle produced beef and dairy products with significant levels of Omega-3s and CLA. Grain fed cows produce almost none of these key fatty acids. Cage free chickens who are allowed to roam outside and eat bugs have a lot of natural Omega-3 in their egg yolks. Factory raised chickens do not.
Another issue is the much higher exposure to toxins than in the past. Almost everything people use utilizes chemicals in its production, and processed foods include far more chemicals than they used to. Your body requires more of certain nutrients when trying to detox dangerous substances.
Beyond that, far fewer people eat whole foods all that often any more. Millions live primarily on processed foods and are almost certainly not getting optimal amounts of all nutrients. Of course, there’s also the issue of people spending less time outside in the sun too and what that’s done to Vitamin D levels, raising cancer, heart disease, and depression rates.
Vitamin D is not found in milk. It is added, and is the same chemical that you will find in a supplement. Getting adequate amounts of vitamins solely from foods is almost impossible if you are older. So is overdosing from most vitamins as most are water soluble. Even fat soluble vitamins would be hard to overdo unless you take massive amounts.
Of course, you can overdo anything. I had a health-conscious friend who was sold on juicing. He actually consumed enough carrot juice to overdose on vitamin A and turned his skin orange. It wasn’t lethal, but he did become ill and was the butt of jokes for quite a while.
The perfect diet only exists in heaven, and I hope to enjoy it someday. Until then, we’ll all just have to muddle along and do our best.