- For most people of any age, a normal vitamin D level is a serum 25-hydroxyvitamin D of 20 ng/mL (50 nmol/L) or higher, which the U.S. Food and Nutrition Board considers adequate for bone and overall health.
- The standard reference range does not change by age or sex: the same 20 ng/mL adequacy cutoff applies to infants, children, adults, and older adults, and to both men and women.
- The Endocrine Society sets a stricter sufficiency threshold of above 30 ng/mL, so a result between 20 and 30 ng/mL may be called adequate by one standard and insufficient by another.
What is a normal vitamin D level?
A normal vitamin D level is a serum 25-hydroxyvitamin D, written 25(OH)D, of 20 ng/mL (50 nmol/L) or higher, the cutoff the U.S. Food and Nutrition Board treats as adequate for nearly everyone (NIH Office of Dietary Supplements). The same body considers below 12 ng/mL (30 nmol/L) a true deficiency and the 12 to 20 ng/mL band as inadequate or at risk. Note that the optimal target is debated. The Endocrine Society defines sufficiency as above 30 ng/mL and suggests a preferred range of 40 to 60 ng/mL for patients it treats (StatPearls, NCBI).
Why two numbers? The 20 ng/mL figure comes from a population standard built around bone health, while the 30 ng/mL figure comes from clinical guidelines for diagnosing and treating deficiency. Your lab report usually flags one of them, so the “normal” label you see depends on which standard the lab follows.
One vitamin, two units: results come in ng/mL or nmol/L. To convert, multiply ng/mL by 2.5. So 20 ng/mL equals 50 nmol/L, and 30 ng/mL equals 75 nmol/L.
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Vitamin D normal range by age
The vitamin D reference range does not shift with age. Across infants, children, adults, and seniors, a 25(OH)D of 20 ng/mL (50 nmol/L) or higher is the adequacy cutoff used by the Food and Nutrition Board, and below 12 ng/mL (30 nmol/L) signals deficiency at every age (NIH Office of Dietary Supplements). What does change by age is how much vitamin D you need to consume to reach that range, which is why the recommended intake climbs from 400 IU in infancy to 800 IU after age 70.
The table below pairs the constant blood reference range with the age-specific recommended intake. Intake values are the Recommended Dietary Allowance, except infant values, which are an Adequate Intake (NIH Office of Dietary Supplements).
| Age group (both sexes) | Normal 25(OH)D range | Recommended daily intake |
|---|---|---|
| Infants, 0 to 12 months | ≥ 20 ng/mL (50 nmol/L) | 400 IU (10 mcg), Adequate Intake |
| Children, 1 to 13 years | ≥ 20 ng/mL (50 nmol/L) | 600 IU (15 mcg) |
| Teens, 14 to 18 years | ≥ 20 ng/mL (50 nmol/L) | 600 IU (15 mcg) |
| Adults, 19 to 70 years | ≥ 20 ng/mL (50 nmol/L) | 600 IU (15 mcg) |
| Older adults, 71+ years | ≥ 20 ng/mL (50 nmol/L) | 800 IU (20 mcg) |
| Pregnancy and lactation | ≥ 20 ng/mL (50 nmol/L) | 600 IU (15 mcg) |
Reading the bands: below 12 ng/mL is deficient, 12 to 20 ng/mL is inadequate or at risk, 20 ng/mL and above is adequate, and consistently above 50 ng/mL (125 nmol/L) may bring no added benefit and could cause harm (NIH Office of Dietary Supplements).
How does sex change the range?
Sex does not change the vitamin D reference range. The 20 ng/mL adequacy cutoff and the deficiency threshold below 12 ng/mL apply identically to men and women, and the recommended daily intake is also the same for both sexes within each age band, for example 600 IU for adults 19 to 70 (NIH Office of Dietary Supplements). There is no separate male or female normal range the way there is for hemoglobin or creatinine.
Sex still influences your real-world status, just not the cutoff. Women face higher demand during pregnancy and breastfeeding and a sharper drop in bone-protective hormones after menopause, which raises the stakes of staying above the line. Body composition matters too, because vitamin D is fat-soluble and people with more body fat may need higher intake to reach the same blood level. These are reasons your number may differ, not reasons the target differs.
What makes vitamin D rise or fall with age?
Vitamin D status tends to fall with age mainly because aging skin makes less of it. After about age 70, the skin’s capacity to synthesize vitamin D from sunlight drops to roughly a quarter of what it was in young adulthood, which is the central reason the recommended intake rises to 800 IU at 71 and older (NIH Office of Dietary Supplements). Older adults also spend less time outdoors and absorb dietary vitamin D less efficiently.
Several forces push the number around at any age:
- Sun exposure: latitude, season, sunscreen, and indoor lifestyles all cut skin production. Winter months reliably lower levels.
- Skin tone: higher melanin slows synthesis, so darker-skinned people often have lower 25(OH)D for the same sun.
- Body fat: vitamin D is stored in fat tissue, which can lower the amount circulating in blood.
- Gut and kidney health: conditions like Crohn disease, celiac disease, and chronic kidney disease impair absorption or activation.
- Diet and supplements: few foods are naturally rich in vitamin D, so fortified foods and supplements drive most intake.
When is an out-of-range result a concern?
An out-of-range result is a concern when 25(OH)D falls below 12 ng/mL (30 nmol/L), which the Food and Nutrition Board defines as deficiency and which is linked to rickets in children and osteomalacia, or soft bones, in adults (NIH Office of Dietary Supplements). A result in the 12 to 20 ng/mL band is inadequate and usually prompts your clinician to recommend more vitamin D, though it is less urgent than frank deficiency.
High results matter too. Vitamin D toxicity is rare and almost always caused by over-supplementation rather than sun or food. Levels above 50 ng/mL (125 nmol/L) may offer no extra benefit, and concentrations over 150 ng/mL (375 nmol/L) can cause hypercalcemia, with nausea, weakness, frequent urination, and in severe cases kidney damage (StatPearls, NCBI). The takeaway: more is not always better.
Always read your result against the specific range printed on your lab report, since a value near 25 ng/mL can read as normal under the Food and Nutrition Board standard yet insufficient under Endocrine Society guidance. Your clinician interprets the number alongside your age, symptoms, calcium, and bone health.
Frequently asked questions
Is a vitamin D level of 30 good?
A level of 30 ng/mL (75 nmol/L) is adequate by the Food and Nutrition Board standard and sits right at the Endocrine Society’s sufficiency threshold of above 30 ng/mL. It is a solid result for most people, though some clinicians aim a little higher.
What vitamin D level is too low?
Below 12 ng/mL (30 nmol/L) is deficient and warrants treatment, per the NIH Office of Dietary Supplements. A level of 12 to 20 ng/mL is considered inadequate and usually prompts a clinician to recommend more vitamin D through diet or supplements.
Does the normal vitamin D range differ for seniors?
No. The blood reference range stays at 20 ng/mL or higher for older adults, the same as for younger people. What changes is the recommended daily intake, which rises to 800 IU at age 71 and above because aging skin makes less vitamin D.
What is the ideal vitamin D level by some experts?
The Endocrine Society suggests a preferred range of 40 to 60 ng/mL for patients it treats, higher than the 20 ng/mL population adequacy cutoff (StatPearls, NCBI). There is no universal agreement on an optimal target, so discuss your goal with your clinician.
Can your vitamin D level be too high?
Yes. Levels above 50 ng/mL (125 nmol/L) may bring no added benefit, and above 150 ng/mL (375 nmol/L) can cause toxicity with high blood calcium, nausea, and kidney problems. Toxicity comes from excess supplements, not sun or food.
Sources
- NIH Office of Dietary Supplements, Vitamin D Health Professional Fact Sheet
- StatPearls (NCBI Bookshelf), Vitamin D
- StatPearls (NCBI Bookshelf), Vitamin D Deficiency
- Endocrine Society Clinical Practice Guideline, Journal of Clinical Endocrinology and Metabolism
This article is for general educational purposes and is not medical advice. It cannot diagnose or treat you and does not replace your clinician. Always discuss your lab results and any health decisions with a qualified healthcare professional.
