This vitamin calculator (or, in other words, this DRI calculator) shows your dietary reference intake (DRI) for all vitamins according to your age and sex. Depending on the scientific advice, you will see either the Recommended Daily Allowance (RDA) or Adequate Intake (AI) for each vitamin. Read the article below to find out what those terms mean, what is vitamins definition, and to discover what is the difference between fat-soluble vitamins and water-soluble vitamins.

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Disclaimer: We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace the professional advice of a health care provider.

What is vitamin - vitamins definition

The term vitamin was used for the first time by Polish biochemist Casimir Funk in 1912. It comes from Latin vita (meaning "life") and amine, as initially vitamins were thought to contain amino acids, the building blocks of the body (this presumption turned out not to be true).

Vitamins are small organic compounds which are necessary for the proper functioning of our bodies. They are classified as micronutrients because we need them in rather small amounts - usually a few milligrams (mg) a day, or sometimes even micrograms (μg). The human body cannot synthesize most vitamins, therefore we must obtain them from our diet. Vitamin D is an exception, as it can be synthesized in the skin when we are exposed to sunlight.

Insufficient vitamin intake may result in vitamin deficiency, which may manifest as various symptoms and diseases. Due to good food availability and the production of vitamin supplements, vitamin deficiencies are less common nowadays. However, they do still occur in some parts of the world. There are thirteen vitamins, which are grouped into two categories: fat-soluble vitamins and water-soluble vitamins. Read the next sections to find out the difference between them.

Fat-soluble vitamins definition

There are four fat-soluble vitamins:

  • vitamin A;
  • vitamin D;
  • vitamin E; and
  • vitamin K.

As the name suggests, fat-soluble vitamins are absorbed through the intestinal tract with the help of fats. Vitamins A and D can accumulate in the body and this can result in dangerous hypervitaminosis, which can happen if too many vitamin supplements are taken (although controlled A hypervitaminosis is used as a treatment).

Water-soluble vitamins definition

There are nine water-soluble vitamins:

  • vitamin C;
  • tiamine (B₁);
  • riboflavin (B₂);
  • niacin (B₃);
  • pantothenic acid (B₅);
  • pyridoxine (B₆);
  • biotin (B₇);
  • folic acid (B₉); and
  • cyanocobalamin (B₁₂).

Water-soluble vitamins dissolve easily in water and, in general, are easily excreted from the body. They are not stored in our bodies and therefore we need a consistent intake of these vitamins from our diet.

Vitamin B12 low levels as well as B9 or iron lead to anemia. Especially iron-deficiency anemia may be easily mistaken for thalassemia (a genetic condition which leads to anemia), and to avoid the mix-up use the Mentzer index calculator.

Daily reference intake - DRI definition

Daily reference intake (DRI) is the general term for a set of reference values used to plan and assess the nutrient intake for healthy people. These values may vary by age, sex and physiologic state.
There are three terms associated with DRI:

  • Recommended Dietary Allowance (RDA);
  • Adequate Intake (AI); and
  • Tolerable Upper Intake Level (UL) - a maximum daily intake that is unlikely to cause adverse health effects.

Our vitamin calculator uses RDA and AI values, and we describe them in detail below.

Recommended Dietary Allowance (RDA) is the average amount of a nutrient a healthy person should consume each day. Consuming an RDA dietary intake level for each nutrient is sufficient to meet the nutrient requirements in nearly all (97–98 percent) healthy individuals.

RDA can vary by age, gender, and physiological state (pregnant or breastfeeding women).
Our daily vitamin intake calculator uses RDA values when possible, so it can be called an RDA calculator as well.

What does adequate intake mean?

Adequate intake is established when not enough information is available from scientific research to determine RDA. In other words, the AI is believed to cover the needs of all healthy individuals, but a lack of data (or uncertainty in the data) prevents specialists from being able to specify with confidence the percentage of individuals covered by this intake.

How does the daily vitamin calculator (DRI calculator) work?

Let's see how easy it is to use our vitamin calculator.

  1. First of all, you need to choose the age.
  2. Then, choose sex.
  3. Finally, choose the vitamin you are interested in.

That's it! You will see the recommended daily allowance for your chosen vitamin, based on your age and sex.

The data comes from Food and Nutrition Board, Institute of Medicine, National Academies and shows RDA intake levels when possible.

Joanna Michałowska, PhD candidate
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