Talk to your doctor before you begin taking a dietary supplement. They can tell you about the benefits and risks of each supplement. Make sure they know about anything you already take. This includes all medicines, prescription and over-the-counter. Some of these can interact with supplements. Read the ingredient list to make sure you know what else is in them. Do not take more than the recommended dosage on the label, unless your doctor approves it. Just because a supplement is advertised as “natural” doesn’t mean it’s safe.
However, the Norwegian authorities do admit that vitamin D supplements are needed during part of the year.  Only part of the year? One third of Norway is within the Arctic Circle. Norway has far too little sunshine (especially during winter months) to get adequate levels of vitamin D from UVB radiation on the skin. The authorities also recommend that pregnant women take folic acid to prevent birth defects, and omega-3-fatty acids may be advisable for those who do not eat fish regularly. Norwegians have a long tradition of giving children cod liver oil, which in a daily tablespoon provides enough vitamin A and D and essential fatty acids to cover basic needs.
A BMI of 25 to 29.9 is considered overweight and one 30 or above is considered obese. For an idea of what this means, a 5-foot 5-inch woman who weighs 150 pounds is overweight with a BMI of 25. At 180 pounds, she would be considered obese, with a BMI of 30. Keep in mind that the tables aren't always accurate, especially if you have a high muscle mass; are pregnant, nursing, frail or elderly; or if you are a teenager (i.e., still growing).
Mental stress increases the excretion and hence the need for many nutrients. Among the most important are magnesium and vitamin C, both of which are used by the body in larger quantities during periods of physical and mental stress. [24,25] Compared with our past as hunters and gatherers, today´s stress is often of a more permanent nature. Instead of experiencing occasional situations where we had to fight or flee, many of us live with recurring stress day in and out.
Access to correct information about food and essential nutrients, including knowledge about the importance of food for health is a fundamental human right. Such information should not only provide a summary of the nutrient content of food, but in our opinion should also explain how dietary supplements can counteract deficiencies and prevent and reverse disease caused by nutrient deficiencies. We should be free to purchase quality-controlled supplements of essential nutrients and to use them to counteract aging and damage from stress as part of a long-term health plan. The right to reject recommendations by doctors for symptomatic treatment with synthetic, some times life-threatening, drugs to alleviate symptoms should be included. [48,49]
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.
The American Academy of Pediatrics, in collaboration with the broader medical community, is educating doctors and nurses across the country about obesity to ensure that they regularly monitor children’s BMIs, provide counseling for healthy eating early on, and, for the first-time ever, write a prescription for parents laying out the simple things they can do to increase healthy eating and active play.
^ Fortmann, SP; Burda, BU; Senger, CA; Lin, JS; Whitlock, EP (Nov 12, 2013). "Vitamin and Mineral Supplements in the Primary Prevention of Cardiovascular Disease and Cancer: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force". Annals of Internal Medicine. 159 (12): 824–834. doi:10.7326/0003-4819-159-12-201312170-00729. PMID 24217421.