When it comes to vitamins and minerals, the Recommended Daily Allowance (RDA) is the average daily intake that a person needs to stay healthy and avoid deficiencies. Men and women have different vitamin and mineral requirements, which are measured in milligrams and micrograms. Vitamin A, also known as retinol, is a fat-soluble vitamin with an RDA of 700 micrograms for women and 900 micrograms for men. It can be found in many dairy products and yellow or orange fruits and vegetables.
The B vitamins, which make up the vitamin B complex, also have different recommended daily doses. According to the United States Department of Agriculture (USDA), most Americans don't get their recommended daily dose of B vitamins in their daily nutrition. Vitamin C is a water-soluble vitamin that contains antioxidants that promote healthy tissue growth. The recommended daily dose for men is 90 milligrams and 75 milligrams for women. Vitamin C is found in many fruits and vegetables, and it can help the body absorb iron better if there is an iron deficiency.
Vitamin D is an essential fat-soluble vitamin that is activated by ultraviolet (UV) light. In addition to sun exposure, it can be found in cod liver oil, fatty fish, fortified juices, milk, and cereals. The recommended daily dose for children and adults is 15 micrograms (600 IU), while for people age 70 and older it's 20 micrograms (800 IU).Vitamin E is an important vitamin for organ function, with a recommended daily dose of 15 milligrams. Sources of vitamin E include vegetable oils, avocados, spinach, seeds and nuts, and whole grains.
Vitamin K is essential for blood clotting, with an RDA of 120 micrograms for men and 90 micrograms for women. This protein-rich vitamin is found primarily in green leafy vegetables. Iron helps carry oxygen in the blood; men and women should consume between 8 and 18 milligrams of iron a day. Iron can be found in red meat, green leafy vegetables, and legumes. When selecting a supplement, calcium citrate is better absorbed than calcium carbonate by 22 to 27%, so it may be a better option for someone who wants to get a higher dose of absorbable calcium per serving.
While supplements are generally not necessary for healthy adults and children, some populations may benefit from dietary supplements. However, it's important to research the type and level of ingredients before taking any supplements as there are risks of side effects, toxicity, and interactions with medications, food and alcohol. A questionnaire can be a starting point to help you determine what vitamins and supplements you really need for a healthy lifestyle. Preformed vitamin A is already in the correct biological form while carotenoids must be converted to retinol in the body. Using sunscreen frequently, living far north or south of the equator, staying at home and having darker skin are risk factors for vitamin D deficiency. Finally, always tell your doctor about any vitamins or supplements you plan to take, especially if you have a health problem or take medications regularly.
Taking the time to research and learn about vitamins can pay off in the long run.