Vitamin Calculator

How this vitamin calculator works

This vitamin calculator estimates daily target ranges for key vitamins and minerals based on your age, sex, pregnancy or lactation status, and diet pattern. It then compares those targets with your current intake (if you enter it) and flags potential shortfalls or excesses.

The ranges are inspired by widely used dietary reference intakes (DRIs) such as the Recommended Dietary Allowance (RDA) or Adequate Intake (AI) for generally healthy adults. Values are rounded and simplified so they are easier to interpret.

Vitamins and minerals included

The tool currently covers:

• Vitamin A (retinol activity equivalents, mcg RAE)
• Vitamin C (mg)
• Vitamin D (IU)
• Vitamin E (mg)
• Vitamin K (mcg)
• Thiamin – vitamin B1 (mg)
• Riboflavin – vitamin B2 (mg)
• Niacin – vitamin B3 (mg)
• Vitamin B6 (mg)
• Folate (mcg dietary folate equivalents)
• Vitamin B12 (mcg)
• Calcium (mg)
• Iron (mg)
• Magnesium (mg)
• Zinc (mg)

Interpreting the results

For each nutrient, the calculator shows a recommended range and your estimated intake (if provided). The status column uses three simple categories:

• Within range – your intake falls inside the suggested range.
• Below range – your intake is below the lower end of the range and may be insufficient over time.
• Above range – your intake is above the upper end of the range and may be unnecessary or risky, especially from supplements.

These categories are only a starting point. Blood tests, symptoms, medications, absorption issues and medical conditions all matter. Always discuss concerns with a qualified healthcare professional.

Key assumptions and limitations

• The calculator is designed for adults and teenagers aged 14 years and older.
• It assumes generally healthy individuals without specific medical conditions or malabsorption syndromes.
• It does not calculate tolerable upper intake levels (ULs) explicitly, but the upper end of the range is usually below or near typical ULs for long‑term intake in healthy adults.
• Vitamin and mineral needs can be higher or lower in chronic disease, after surgery, with certain medications, or in underweight/overweight states.

Why diet pattern matters

Your diet pattern (omnivore, vegetarian, vegan) does not change the basic physiological requirement for a nutrient, but it does change how easy it is to meet that requirement from food alone. The calculator uses your diet pattern to highlight nutrients that deserve extra attention:

• Vegetarian: iron, zinc, vitamin B12 (if limited dairy/eggs), omega‑3 fats (not shown here), vitamin D.
• Vegan: vitamin B12, vitamin D, iodine, calcium, iron, zinc, omega‑3 fats.

If you follow a plant‑based diet, consider fortified foods and, where appropriate, supplements under professional guidance.

Safety: vitamins can be too high as well as too low

Water‑soluble vitamins (like vitamin C and most B vitamins) are generally safer at higher intakes because excess is excreted in urine. However, very high doses can still cause side effects (for example, high‑dose vitamin B6 can cause nerve problems).

Fat‑soluble vitamins (A, D, E, K) are stored in the body and can build up over time. Long‑term intakes above the upper limit can cause toxicity. This is especially important for:

• Vitamin A: excessive preformed vitamin A (retinol) can cause liver and bone problems and is unsafe in pregnancy.
• Vitamin D: very high doses can raise blood calcium and damage kidneys and blood vessels.
• Vitamin E: high‑dose supplements may increase bleeding risk in some people.

Never start high‑dose vitamin or mineral supplements without discussing them with your doctor or pharmacist, especially if you are pregnant, breastfeeding, have kidney or liver disease, or take prescription medications.

Practical tips to improve your vitamin intake

• Base your diet on a variety of minimally processed foods: vegetables, fruits, whole grains, legumes, nuts, seeds and quality protein sources.
• Include some sources of healthy fats (e.g., olive oil, nuts, seeds, oily fish) to help absorb fat‑soluble vitamins.
• Use fortified foods strategically (e.g., fortified plant milks for calcium, vitamin D and B12 if you are vegan).
• Limit reliance on single “mega‑dose” supplements unless prescribed; balanced multivitamins at modest doses are usually safer.
• Re‑check your intake if your diet, weight, health status or medications change significantly.

Medical disclaimer

This vitamin calculator is an educational tool only. It does not provide medical or nutrition advice, does not diagnose or treat any condition, and is not a substitute for consultation with a physician, dietitian or other qualified health professional. Never ignore professional medical advice or delay seeking it because of something you read here.