For most adults, a normal level of vitamin D in the blood is 20 nanograms per milliliter or above. The amount of vitamin D a person needs per day depends on their age.
Normal vitamin D levels.
|0–12 months||10 micrograms (mcg) or 400 international units (IU)|
|1–70 years||15 mcg or 600 IU|
|71+ years||20 mcg or 800 IU|
A level of 20 nanograms/milliliter to 50 ng/mL is considered adequate for healthy people. A level less than 12 ng/mL indicates vitamin D deficiency.
Adults aged up to 70 years old should be getting at least 600 IU. Adults older than 70 should be getting at least 800 IU of vitamin D.
The Institute of Medicine has placed the recommended dietary allowance, or RDA, for vitamin D at 600 international units (IU) per day for young adults and 800 IU per day for adults older than 70. Other experts suggest that adults’ vitamin D needs are much higher.
Vitamin D Recommendations According to the report, children older than 1 years old and adults up to 70 years of age are recommended to consume 600 IU of vitamin D daily and adults greater than 70 years of age are recommended to consume 800 IU of vitamin D daily .
Vitamin D recommended intake is at 400–800 IU/day or 10–20 micrograms. However, some studies suggest that a higher daily intake of 1,000–4,000 IU (25–100 micrograms) is needed to maintain optimal blood levels.
Low blood levels of 25-hydroxy vitamin D usually mean one (or more) of the following: you aren’t eating a balanced, complete diet. your intestines aren’t absorbing the vitamin properly. you’re not spending enough time outside to absorb adequate vitamin D levels through sun exposure.
The truth is, we do need vitamin D to stay healthy, but 5000 IU (units) of vitamin D in a daily tablet is more than most people need. The recommended maximum daily limit of vitamin D in healthy people is 4000 IU. That includes intakes from food, beverages, and supplements.
While the upper limit of this recommendation is 2,000 IU per day, research shows that high doses of vitamin D (10,000 to 50,000 IU daily) may be necessary for patients who have a history of malabsorption. While vitamin D toxicity (also called hypervitaminosis D) is rare, it can have serious side effects.
The Endocrine Society Practice Guidelines recommend that up to 10,000 IUs daily was safe for adults. This is in contrast to the recommended UL at 4,000 IU/d from the IOM.
Scientists found that taking 1,000 IU (25 mcg) of vitamin D daily reduced heart disease risk by 10% ( 16 ). Based on current research, it seems that consuming 1,000–4,000 IU (25–100 mcg) of vitamin D daily should be ideal for most people to reach healthy vitamin D blood levels.
The National Academy of Medicine recommend a daily intake of 600 international units (IU) for adults aged 19–70 years and 800 IU per day for individuals aged 70+ years.
While it is true that excess vitamin D can be dangerous, it is very uncommon to have excess vitamin D when taking 8,000 units or less daily. (Some people will need more than that, but doses in excess of 8,000 IU should be guided by blood levels.
Based on the evidence for bone benefits, however, the IOM panel increased the RDA for vitamin D to 600 IU for people up to age 70 and to 800 IU for those over 70. That’s a fairly sizable boost over the previous recommendations of 200 IU per day through age 50, 400 IU for ages 51 to 70, and 600 IU for ages over 70.
The current daily recommended amount of vitamin D is 600 IU per day for adults under the age of 70, and 800 IU for older adults. Up to 4,000 IU per day is generally considered the safe upper limit, however, doses up to 10,000 IU/day have not been shown to cause toxicity.