When eating healthily, and especially when following Paleolithic or Primal eating habits, you have no need to worry much about supplementing. Most of the vitamins and minerals necessary are provided from the variety of foods available.
Although, our environment has changed (and so has the nutrient density in our foods), so there are a few supplements that practically anyone could benefit from.
Fish Oil Due to our over consumption of omega 6 to omega 3 from things like poor quality meat, vegetable oils, and processed foods, high quality fish oil (or the more expensive route of grass-fed meats, free-range eggs, and wild-caught fish) is generally necessary to some degree.
Vitamin D Vitamin D works with Magnesium and Calcium to ensure strong bones. It has also shown to fight off some forms of cancer, and provide support to the immune system. It is suggested by Mark Sisson to allow your body 4,000IU-10,000IU daily.
Probiotics Probiotics are essentially live and active bacterial cultures. They improve your gut flora which aids in digestion, metabolic health and weight loss. This, accompanied by many other health benefits and the fact that you can not overdose (unless you have a severe condition like SIBO), makes probiotics one of the most influential supplements.
Multivitamin If you are eating a well balanced diet, avoiding processed foods, grains, and legumes and sourcing your vitamins from a wide variety of fruits, vegetables, and high quality meat, you should be fine. BUT, most of us are not quite so perfect and a good, food derived multivitamin should help with any deficiencies you might have.
Magnesium Things like stress and alcohol intake can negatively affect the magnesium levels in the body. In addition to resolving these issues, Magnesium also allows our bodies to better utilize Calcium and Vitamin D.
Some may even go as far as to say that no supplements besides those listed here are necessary with the correct diet.
What do your eating habits look like? Do you supplement with anything? Did I miss something of extreme importance?