Compared to pharmaceutical drugs, supplements of most essential nutrients are quite harmless. However, some supplements may have poor quality, or contain toxic metals such as lead or cadmium. Therefore, it is the duty of our authorities to ensure that potentially hazardous products or supplements of poor quality are not sold, and that consumers are offered fair prices in a free market. An example where the Norwegian authorities do not follow up such basic duties is that pharmacies demand more than 1,600 Norwegian Kroner (about $190) per kg of vitamin C in powder form, which would cost less than $20 with free competition and no restrictions in permitted doses or outlets.
We've heard a lot of encouraging news about supplements. A series of studies hailed vitamin D as a possible defense against a long list of diseases, including cancer, diabetes, depression, and even the common cold. Omega-3 fatty acids have been touted for warding off strokes and other cardiovascular events. And antioxidants such as vitamins C and E and beta carotene were seen as promising silver bullets against heart disease, cancer, and even Alzheimer's disease.
A 45-year-old woman who gets less than 30 minutes of daily physical activity in addition to her normal routine should consume six ounce of grains; two and a half cups of vegetables; one and a half cups of fruit; three cups of milk; five ounces of meat and/or beans; five teaspoons of oil; and just 195 calories of additional fat and sugar. With a higher level of daily activity (30 to 60 minutes), this woman would be able to consume a little more in certain food groups: her fruit intake could rise to two cups; meat and beans to five and a half ounces; oils to six teaspoons; and extra fat and sugar to 265 calories.
As the science of nutrition continually evolves, researchers recognize that nutrients needed to maintain a healthy lifestyle must be tailored to the individual for maximum effectiveness. Recognizing that people are not all alike and that one size does not fit all when it comes to planning and achieving a healthful diet, the Institute of Medicine's dietary guidelines, titled "Dietary Reference Intakes for Macronutrients," stress the importance of balancing diet with exercise and recommends total calories based on an individual's height, weight and gender for each of four different levels of physical activity.
The saturated fat, sodium, and added sugars found in foods and beverages are important for you to think about as you build your healthy eating style. Saturated fat and sodium are sometimes found naturally in foods and beverages. Sugars, sodium, and ingredients high in saturated fat can also be added during processing or preparing foods and beverages.
For example, while increased consumption of fruits and vegetables are related to decreases in mortality, cardiovascular diseases and cancers, supplementation with key factors found in fruits and vegetable, like antioxidants, vitamins, or minerals, do not help and some have been found to be harmful in some cases. In general as of 2016, robust clinical data is lacking, that shows that any kind of dietary supplementation does more good than harm for people who are healthy and eating a reasonable diet but there is clear data showing that dietary pattern and lifestyle choices are associated with health outcomes.