CitedDose

Vitamin D: the 2024 Endocrine Society guideline in plain language

The 2024 Endocrine Society guideline recommends vitamin D supplements beyond the standard daily allowance for four groups only: children and teenagers aged 1 to 18, adults aged 75 and over, pregnant people, and adults with high-risk prediabetes. For healthy adults under 75 it advises sticking to the recommended daily allowance (600 IU to age 70, 800 IU after) and advises against routine vitamin D blood tests. It also dropped the earlier target blood level of 30 ng/mL.

Last reviewed: 2026-10-06

Run your own numbers: Vitamin D dosage calculator

The recommendations at a glance

GroupSupplement beyond the daily allowance?WhyDoses used in the trials
Children and teens, 1 to 18YesPrevents nutritional rickets; may lower respiratory infections300 to 2,000 IU a day, average about 1,200
Adults 19 to 49NoNo demonstrated benefit in healthy adults
Adults 50 to 74NoLarge trials found no reduction in fractures, cancer or heart disease
Adults 75 and overYesMay lower mortality400 to 3,333 IU a day, average about 900
PregnancyYesMay lower pre-eclampsia, preterm birth, small-for-gestational-age birth and neonatal death600 to 5,000 IU a day, average about 2,500
High-risk prediabetesYes, with lifestyle changeMay reduce progression to type 2 diabetes842 to 7,543 IU a day, average about 3,500

"No" in this table means no supplement beyond the recommended daily allowance. Everyone still needs that allowance: 600 IU a day from age 1 to 70 and 800 IU after 70, from all sources.

The guideline did not name a single best dose for any group. The averages above describe what the trials used and are not prescriptions.

The three biggest changes from 2011

1. No more routine blood tests

The panel advises against routine 25-hydroxyvitamin D testing in healthy people, including in adults with darker skin and adults with obesity, two groups often tested because their levels run lower. The reasoning is that no trials show that screening and treating to a number improves health, and the test adds cost and leads to overtreatment.

2. No more target level

The 2011 guideline defined deficiency as below 20 ng/mL and sufficiency as 30 ng/mL or above, which labeled a large share of the population insufficient. The 2024 guideline no longer endorses these thresholds for healthy people. Laboratories and doctors still use them for clinical judgment, and levels below 12 ng/mL remain a clear concern for bone health.

3. Daily, lower doses instead of large occasional ones

For adults over 50 who do take vitamin D, the panel suggests daily lower-dose vitamin D over weekly, monthly or yearly high doses. Some trials of large intermittent doses in older adults found more falls and fractures, not fewer.

Why the advice got more conservative

Between 2011 and 2024 several large randomized trials reported. The biggest, VITAL, gave 2,000 IU a day or placebo to 25,871 generally healthy American adults for about five years and found no reduction in cancer or major cardiovascular events; a follow-up analysis found no reduction in fractures. Trials like this shifted the question from "what level should everyone reach?" to "which specific groups benefit?"

The four groups in the table are where pooled trial data showed a likely benefit. The panel graded most of these as conditional recommendations based on low to moderate certainty evidence, which is why the wording is "suggest" and not "recommend."

Where the guideline sits next to other advice

SourcePosition
Institute of Medicine 2011600 IU a day to age 70, 800 IU after; upper limit 4,000 IU; 20 ng/mL adequate for nearly everyone
Endocrine Society 2011Target 30 ng/mL; test people at risk; 1,500 to 2,000 IU a day for many adults
Endocrine Society 2024Daily allowance for most; extra for four groups; no routine testing; no target level

What to do with this

  • Healthy and under 75: aim for the daily allowance. If you get little sun and eat little oily fish or fortified food, a 600 to 1,000 IU daily supplement covers it. There is no need for a blood test first.
  • 75 or over: a daily supplement is suggested. Around 800 to 1,000 IU is in line with the trials.
  • Pregnant: ask your maternity provider about a dose; many prenatal vitamins contain only 400 IU.
  • Prediabetes: discuss vitamin D with your doctor as an addition to diet, activity and weight management, not a replacement.
  • Everyone: stay at or below 4,000 IU a day unless a doctor is monitoring you.

Limits worth knowing: most trial participants were not vitamin D deficient at the start, so the guideline says less about people with very low levels, and most trials were in North America and Europe.

Run your own numbers: Vitamin D dosage calculator

Frequently asked questions

Should healthy adults take vitamin D supplements?

The 2024 guideline suggests against supplementing beyond the recommended daily allowance for healthy adults under 75. That allowance is 600 IU (15 micrograms) a day to age 70 and 800 IU (20 micrograms) after, from food, sun and supplements combined. A modest supplement is reasonable if your diet and sun exposure are low.

Should I get my vitamin D level tested?

Not routinely, if you are healthy. The guideline advises against routine 25-hydroxyvitamin D testing in the general population, including people with darker skin or obesity, because no trial evidence shows that testing and treating to a target improves outcomes. Testing remains appropriate for specific medical conditions.

How much vitamin D should someone over 75 take?

The guideline does not set one dose. The trials it relied on used roughly 400 to 3,300 IU a day, averaging about 900 IU. It favors daily lower doses over large weekly or monthly doses in adults over 50.

Is 30 ng/mL still the target vitamin D level?

No. The 2011 Endocrine Society guideline defined sufficiency as 30 ng/mL or more. The 2024 guideline no longer endorses specific target levels, because trials did not establish thresholds that predict benefit.

Does vitamin D prevent diabetes?

In adults with high-risk prediabetes, the guideline suggests vitamin D in addition to lifestyle changes, based on pooled trial data showing a lower rate of progression to type 2 diabetes. Trial doses averaged about 3,500 IU a day, which should be taken with medical supervision.

Does this guideline apply if I have osteoporosis or kidney disease?

No. It covers disease prevention in generally healthy people. Established conditions that affect vitamin D or calcium, such as osteoporosis, malabsorption, chronic kidney disease or hyperparathyroidism, are managed individually by a doctor.

Sources

  1. Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the prevention of disease: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2024;109(8):1907-1947
  2. Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. 2011 (recommended daily allowance and 4,000 IU upper limit)
  3. Manson JE, et al. Vitamin D supplements and prevention of cancer and cardiovascular disease (VITAL). N Engl J Med. 2019;380(1):33-44 (25,871 adults, 2,000 IU a day, no reduction in primary outcomes)
  4. Pittas AG, et al. Vitamin D and risk for type 2 diabetes in people with prediabetes: a systematic review and meta-analysis of individual participant data. Ann Intern Med. 2023;176(3):355-363
  5. NIH Office of Dietary Supplements. Vitamin D fact sheet for health professionals

Related calculators

  • Does collagen work for skin? What the 2026 meta-analysis foundA plain-language reading of the 2026 meta-analysis of collagen peptide trials: real gains in hydration and elasticity, no reliable effect on wrinkles, and why trial funding matters.
  • How much protein per meal?The evidence on protein per meal: the 0.4 g/kg guideline, why the old 20 to 30 g ceiling was too simple, what the 2023 100 g study found, and a per-meal table by body weight.
  • Creatine loading vs daily dosingDo you need a creatine loading phase? The 1996 study that answered it, how long each method takes to saturate muscle, the side effects of loading, and who should actually load.
  • Protein needs over 60: why the RDA is too lowTwo expert groups recommend 1.0 to 1.2 g of protein per kg a day for healthy older adults, more when ill, with 25 to 30 g per meal. What the evidence says, a table by body weight, and how to actually eat it.
  • Vitamin D dose by body weightA 17,614-person study found the same vitamin D dose raises blood levels far less in heavier people, and that overweight adults need about 1.5 times and obese adults 2 to 3 times the dose. How to size a daily dose by weight, and where the 4,000 IU ceiling fits.
  • Collagen dosage calculatorHow many grams of hydrolyzed collagen per day for skin, joints, bone density or muscle, based on the doses used in randomized trials, with how long until you should expect results.
  • Daily protein intake calculatorCalculate grams of protein per day from body weight, activity and goal, using the RDA (0.8 g/kg), the ISSN position stand (1.4 to 2.0 g/kg for training) and higher ranges for fat loss and older adults.
  • Creatine dosage calculatorWork out your creatine monohydrate dose: optional loading phase at 0.3 g/kg for 5 to 7 days, or a steady 3 to 5 g a day, with time to saturation and water-weight expectations.
  • Supplement interaction checkerTick the supplements and medication types you take to see documented interactions, absorption conflicts and timing fixes, drawn from NIH Office of Dietary Supplements and clinical pharmacology references.

Educational information only, not medical advice. Results are population estimates from published studies and may not apply to you.