Vitamin IU PPM Converter

Convert vitamins A, D, E from IU to mg, μg, ppm in real-time and check daily recommended intake.

Conversion Results

μg (micrograms) 300 mg (milligrams) 0.3 ppm (parts per million) 0.3

Daily Recommended Intake

Item	IU	Equivalent
For Adults	3,000 IU	900 μg
Upper Limit	10,000 IU	3,000 μg

GUIDE

Learn more

What is IU (International Unit)?

IU (International Unit) is a unit that measures the biological activity of vitamins. Since the same amount of vitamins can have different absorption rates and effects depending on their form, IU standardizes based on biological efficacy rather than weight (mg, μg). For Vitamin A, 1 IU = 0.3 μg retinol or 0.6 μg beta-carotene. For Vitamin D, 1 IU = 0.025 μg. For Vitamin E, 1 IU = 0.67 mg d-α-tocopherol or 1 mg dl-α-tocopherol.

Vitamin A IU Conversion and RAE

Vitamin A is also expressed as Retinol Activity Equivalents (RAE). 1 RAE = 1 μg retinol = 12 μg beta-carotene = 24 μg other carotenoids. In IU, 1 RAE = 3.33 IU (retinol basis). Adult males need 900 μg RAE (3,000 IU) daily, adult females need 700 μg RAE (2,333 IU). The upper limit is 3,000 μg RAE (10,000 IU).

Vitamin D IU Conversion and Sunlight Synthesis

The daily recommended intake of Vitamin D is 600 IU (15 μg) for adults, 800 IU (20 μg) for those over 71. The upper limit is 4,000 IU (100 μg). 15-30 minutes of sunlight exposure synthesizes about 10,000-25,000 IU of Vitamin D in the body. Salmon (100g) contains about 400-800 IU, one egg yolk contains 40 IU.

Vitamin E IU Conversion and Antioxidant Effects

Vitamin E is classified into natural d-α-tocopherol and synthetic dl-α-tocopherol. Natural form: 1 IU = 0.67 mg, synthetic form: 1 IU = 1 mg. Daily recommended intake for adults is 15 mg (22.4 IU natural or 33.3 IU synthetic). Almonds (28g, 23 nuts) contain about 7.3 mg (10.9 IU).

Understanding ppm and Nutritional Labeling

ppm (parts per million) is a concentration unit representing one part per million: 1 ppm = 1 mg/kg = 1 μg/g. It is used for food additives, pesticide residues, and heavy metal content. For example, if 1L of water (1kg) contains 100mg of Vitamin C, that is 100 ppm.

Precautions When Choosing Vitamin Supplements

When choosing vitamin supplements, check form (natural/synthetic), content (IU/mg), and absorption rate. Vitamin A in retinol form has higher absorption than beta-carotene, but beta-carotene is safer due to toxicity concerns. Vitamin D3 has higher bioactivity than D2. Natural Vitamin E (d-α-tocopherol) has 2x higher bioavailability than synthetic forms.

Frequently asked questions

Why does each vitamin have a different IU-to-mg conversion factor?

Because IU measures biological activity, not weight. Vitamins A, D, and E have different chemical structures and potencies, so the actual mass (mg or μg) equal to 1 IU is defined separately for each one.

My supplement label lists both IU and mg — which one should I use?

Both describe the same amount, so you can enter either value to convert. Just make sure you compare products using the same unit (either IU or mg) for an accurate comparison.

When is the ppm unit used for vitamins?

ppm (parts per million) expresses very small concentrations, where 1 ppm = 1 mg/kg. It is used for fortified foods and trace additives, and this calculator also shows an equivalent ppm figure for reference alongside the IU/mg conversion.

Is it dangerous to exceed the upper limit?

Exceeding the upper limit slightly for a day or two is not immediately dangerous, but fat-soluble vitamins (A, D, E) accumulate in the body, so sustained overuse raises the risk of liver damage, bone problems, and other side effects.

Do natural and synthetic Vitamin E convert differently?

Yes. Natural d-α-tocopherol converts at 1 IU = 0.67 mg, while synthetic dl-α-tocopherol converts at 1 IU = 1 mg, so the same IU value corresponds to a different mg amount and bioavailability.