Vitamin D supplementation guidelines and blood level targets for health
What it found
Guidelines focused on bone health aim for a vitamin D blood level of 20 ng/mL using 400 to 800 IU daily, while those covering wider health effects aim for 30 ng/mL using 400 to 2,000 IU daily.
The authors say food alone cannot keep levels in the 30 to 50 ng/mL range all year round.
What they found
Studies in people
Different targets for bones
Guidelines focused only on bones suggest a blood level of 20 ng/mL (50 nmol/L). To reach this, they recommend daily doses of 400 to 800 IU depending on age.
Higher targets overall
Guidelines covering wider health effects suggest a blood level of 30 ng/mL (75 nmol/L). They recommend 400 to 2,000 IU per day, adjusted for age, weight, disease status, and ethnicity.
Rare side effects
Taking vitamin D yourself rarely causes problems like too much calcium in the blood or urine. When it happens, it usually comes from taking extremely high doses for a long time.
Treating low levels
For people with blood levels below 20 ng/mL, treatment lasts one to three months. Adults may take 7,000 to 10,000 IU daily, or 50,000 IU weekly, while babies under one month take 1,000 IU daily.
Other findings
Food sources fall short
Natural food sources can raise vitamin D blood levels, but the authors say they are not enough for most people. Food alone cannot maintain levels between 30 and 50 ng/mL (75 to 125 nmol/L) throughout the year.
What the authors conclude
- They advise choosing vitamin D guidelines based on personal factors like age, weight, where you live, and your diet.
- They conclude that regional or national guidelines work better for everyday use than global ones focused only on bones.
- They warn against taking very high doses without medical supervision, noting that more is not always better.
How it was done
Over the past two decades, research showed vitamin D does more than support bones, acting in many organs and tissues. Because different groups published conflicting advice on how much to take, the authors wanted to compare these guidelines and explain which ones fit different needs.
The authors reviewed existing guidelines from scientific groups and agencies about vitamin D doses and target blood levels. They compared rules focused only on bones with rules that also cover other body systems. They looked at recommendations for healthy people, patients with specific diseases, and people treating a confirmed deficiency.
What it can’t tell you
- This paper compares existing guidelines rather than running a new trial, so it cannot prove which dose works best for an individual.
- Observational studies linking higher vitamin D levels to better health show a connection, but they cannot prove vitamin D caused the improvement.
Who paid
- Authors work at
- The Children's Memorial Health Institute, Poland; Boston University Medical Center, USA; and Health Research Center, USA
The paper
- Title
- Vitamin D supplementation guidelines
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Pludowski P, Holick MF, Grant WB, et al (2018). Vitamin D supplementation guidelines. The Journal of steroid biochemistry and molecular biology. doi:10.1016/j.jsbmb.2017.01.021Free full textPubMed 28216084DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error