Herbal preparations and nutritional supplements may interact unfavorably with pharmaceutical drugs. For instance, some nutritional supplements recommended for nervous system function may not be recommended for those taking pharmaceutical antidepressants, such as taking 5-HTP, a nutritional supplement for the brain, or the herb St. John's Wort, with prescription antidepressants. Vitamin C should not be taken with aspirin, as it can irritate the stomach and limit absorption. Minerals should be taken in proper proportions to prevent unfavorable interactions; large amounts of zinc may deplete the body of the mineral copper, while too much calcium adversely affects the magnesium levels in the body. Balanced mineral supplements are recommended to alleviate these interactions.
Most Americans get far more protein than they really need. In theory, that may not be wise. Like carbohydrates, protein provides 4 calories per gram, and excess calories from any source will be stored as body fat. Excess dietary protein increases calcium loss in the urine, perhaps raising the risk for osteoporosis ("thin bones," more a worry for women) and kidney stones (a particular worry for men).
I have identified a number of arguments in favor of supplementing the modern diet with essential nutrients, here summarized with 7 headlines. Most people should consider taking a multivitamin supplement containing vitamins and minerals even if they eat a nutritionally balanced diet. Additional nutrients may contribute to better health and, in some cases, can be of vital importance in our modern world. The arguments are presented in random order, i.e. the order does not reflect priority.
The recommended nutrient reference intake (NRI) has been defined by UK authorities and the EU Food Safety Agency as the dose that is adequate for 95 percent of the population.  These authorities have given recommendations for a total of 41 chemical substances,  including 13 vitamins, 17 minerals/trace elements, 9 amino acids and two fatty acids. The problem with such guidelines is that when using the same 0.95 fraction for just 16 of the essential nutrients, the fraction of the overall population that has their needs met with the RDA is less than half (0.9516 = 0.44). Given the above assumption, the proportion of the population having all nutrient needs met falls below 25 percent for 30 nutrients (0.9530 = 0.21). These 25 percent will not necessarily get optimal amounts, just enough so that they probably will have no deficiencies in accordance with established standards. Each individual is different and has different biochemical needs, so we all need different doses of essential nutrients. Many vitamins and minerals can give additional benefit when taken at higher doses.
Say no to sugary drinks. The average American drinks around 45 gallons of soda each year, according to the Beverage Marketing Corporation. Other than the obvious risk of Type 2 diabetes and obesity, consuming sugary beverages can also cause liver damage, premature aging and anxiety. So, instead of sipping packaged juice or soda, go for unsweetened beverages or infused water.
You may have noticed on the blog that I still share sweets and breads and tasty foods like burgers and pasta. And, you’ve probably noticed that I refer to these recipes as “clean” or “healthy.” The way I do this is I’ve become very creative at making delicious foods using sneaky ingredients. Once you get started, it gets easier and easier and you find yourself being able to enjoy all the foods you love, but in a healthier form. How cool is that?
Animal products, such as meat, fish and poultry are good and important sources of iron. Iron from plant sources are found in peas and beans, spinach and other green leafy vegetables, potatoes, and whole-grain and iron-fortified cereal products. The addition of even relatively small amounts of meat or foods containing vitamin C substantially increases the total amount of iron absorbed from the entire meal.
In 2015, the Australian Government's Department of Health published the results of a review of herbal supplements to determine if any were suitable for coverage by health insurance. Establishing guidelines to assess safety and efficacy of botanical supplement products, the European Medicines Agency provided criteria for evaluating and grading the quality of clinical research in preparing monographs about herbal supplements. In the United States, the National Center for Complementary and Integrative Health of the National Institutes of Health provides fact sheets evaluating the safety, potential effectiveness and side effects of many botanical products.