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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

I tested my vitamin D level. What do my results mean?

If you have had your vitamin D levels tested, it’s important to understand what the results mean, and what action you might need to take. The blood test that measures vitamin D is called a 25(OH)D blood test. The results of the blood test can tell you whether you’re getting too little, too much or the right amount of vitamin D. This will help you to decide whether to take more or less supplement, or expose your skin to the sun more.

When you get your test results you will see a number in units of ng/ml, for example, 50 ng/ml. These are the units that health professionals in the United States use. Elsewhere in the world, vitamin D blood test results are given in units of nmol/l.

  • To convert a test result measured in ng/ml to one measured in nmol/l, multiply the ng/ml number by 2.5. For example, 20 ng/ml is the same as 50 nmol/l (20 x 2.5).
  • To convert a test result measured in nmol/l to one measured in ng/ml, divide the nmol/l number by 2.5. For example, 50 nmol/l is the same as 20 ng/ml (50÷2.5).

Here is a quick summary of what different levels mean and what the levels may mean for your health and what to do below.

Note that everybody is different and not everybody achieves the same levels after supplementing with the same amounts. The tables below show on average how much a supplement regimen might raise your blood levels, but you can think of the amounts listed as more of a prediction than a guarantee. This is why you may consider checking your levels twice per year or more, to see if you need to increase or decrease your dosage.

My level is between 0-10 ng/ml

You’re severely deficient in vitamin D by every standard out there, including the Institute of Medicine, the Endocrine Society and the Vitamin D Council.

With a vitamin D level in this range, your health is at risk. You may have low blood calcium levels which can lead to softening of your bones. With very low vitamin D levels you may also have less strength in your muscles and have difficultly moving.

If you want to raise your blood levels starting from 10 ng/ml, you can take the following action (based on an average body weight of 150lbs):

To achieve this level… Take this much supplement per day…
20 ng/ml 1000 IU
30 ng/ml 2200 IU
40 ng/ml 3600 IU
50 ng/ml 5300 IU
60 ng/ml 7400 IU
70 ng/ml 10100 IU

My level is between 10-20 ng/ml

By Endocrine Society and Vitamin D Council standards, you’re still deficient in vitamin D. According to the Institute of Medicine, you’re mildly deficient, or insufficient, in vitamin D. If you’re African American or Hispanic American you’re likely to be in this range.

With vitamin D levels in this range you’re more likely to develop osteoporosis and your bones may be affected because your body isn’t absorbing enough calcium. This means you’re more likely to fracture or break bones and more likely to have a fall. You may also have high levels of parathyroid hormone in your body. Parathyroid hormone controls the levels of calcium and phosphorus in your body and too much can affect your bones.

If you want to raise your blood levels starting from 15 ng/ml, you can take the following action (based on an average body weight of 150lbs):

To achieve this level… Take this much supplement per day…
20 ng/ml 500 IU
30 ng/ml 1700 IU
40 ng/ml 3200 IU
50 ng/ml 4900 IU
60 ng/ml 7000 IU
70 ng/ml 9700 IU

My level is between 20-30 ng/ml

According to the Vitamin D Council, you’re deficient in vitamin D. According to the Endocrine Society, you’re insufficient. By the Institute of Medicine’s standards, you’re getting enough vitamin D. If you’re Caucasian American, you’re likely to have a vitamin D level in this range.

With a vitamin D level in this range you’re less likely to have health problems than when vitamin D is at lower levels. However, your body may still be producing too much parathyroid hormone and not fully absorbing calcium, which can affect your bones.  Research shows that levels above 30 ng/ml may be more likely to prevent bone problems such as fractures.

If you want to raise your blood levels starting from 25 ng/ml, you can take the following action (based on an average body weight of 150lbs):

To achieve this level… Take this much supplement per day…
30 ng/ml 600 IU
40 ng/ml 2000 IU
50 ng/ml 3700 IU
60 ng/ml 5800 IU
70 ng/ml 8600 IU

My level is between 30-40 ng/ml

According to the Vitamin D Council, you’re still not quite sufficient in vitamin D, though your levels are better than most people’s. By Endocrine Society and Institute of Medicine standards, you’re getting enough vitamin D.

The good news is, with vitamin D levels in this range, your body is absorbing calcium well and you should have the right levels of parathyroid hormone. This means strong and healthy bones. In some research studies, vitamin D levels in this range have been shown to reduce your risk of developing cancer and improve your immune system, which fights infection.

If you want to raise your blood levels starting from 35 ng/ml, you can take the following action (based on an average body weight of 150lbs)

To achieve this level… Take this much supplement per day…
40 ng/ml 800 IU
50 ng/ml 2500 IU
60 ng/ml 4600 IU
70 ng/ml 7300 IU

My level is between 40-50 ng/ml

According to most standards, including the Vitamin D Council, Endocrine Society and Institute of Medicine, you are getting enough vitamin D!

These are the levels of vitamin D humans evolved with. If you spent an entire year exposing your full naked body to the sun at the equator, these are the levels of vitamin D you would have. In modern times, these are the levels that hunter gatherers still living traditional outdoor lifestyles in Africa have.

At these levels, vitamin D is working well to control the level of parathyroid hormone and calcium in your body. If you’re breastfeeding you will have vitamin D in your breast milk to pass on to your baby.

Some research studies suggest that these levels of vitamin D are linked to a reduced risk of some cancers and better heart health and circulation. Research also suggests that this level of vitamin D helps to give you a strong immune system to fight infection.

If you want to raise your blood levels starting from 45 ng/ml, you can take the following action (based on an average body weight of 150lbs):

To achieve this level… Take this much supplement per day…
50 ng/ml 900 IU
60 ng/ml 3000 IU
70 ng/ml 5700 IU

My level is between 50-60 ng/ml

You’re getting the right amount of vitamin D by the standards set by the Vitamin D Council and Endocrine Society. The Institute of Medicine, however, doesn’t feel there is enough evidence to say that having a level higher than 50 ng/ml is of any benefit.

Some vitamin D researchers believe that these levels are the best to aim for, though more research is needed to be sure about this.

My level is between 60-80 ng/ml

You’re getting the right amount of vitamin D by the standards set by the Vitamin D Council and Endocrine Society. The Institute of Medicine, however, doesn’t feel there is enough evidence to say that having a level higher than 50 ng/ml is of any benefit.

The Vitamin D Council considers this the “high-normal” range. Research studies have shown that you can achieve these levels just by exposing your skin to the sun, so it’s believed that these are certainly healthy and natural levels.

There isn’t currently enough research to know if there is any benefit to having vitamin D levels this high, instead of levels between 40 ng/ml and 60 ng/ml. However, there is no known danger in keeping your vitamin D level in this 60-80 ng/ml range.

My level is between 80-100 ng/ml

You are still within the normal range according to testing laboratories and the Endocrine Society. The Institute of Medicine, however, doesn’t feel there is enough evidence to say that having a level higher than 50 ng/ml is of any benefit.

These levels are just above what you can naturally achieve by just exposing your skin to the sun. In other words, you can’t achieve these levels without taking a supplement.

There isn’t currently enough research to know if there is any benefit to having levels this high. However, there is no known danger in maintaining levels in this 80-100 ng/ml range.

My level is between 100-150 ng/ml

Although these levels aren’t toxic and aren’t usually harmful, they are thought to be too high. There are no known benefits to having a vitamin D level over 100 ng/ml. A study by a group of researchers in Utah found that levels over 100 ng/ml are linked to a slight increased risk of developing an irregular heart beat called atrial fibrillation.

You should take steps to lower your levels to below 100 ng/ml , unless you are under the supervision of your doctor. To lower your levels, stop taking supplements. After three months, test your vitamin D levels and adjust the amount of supplement you take  once your test results show your level has dropped back down to the normal range.

My level is greater than 150 ng/ml

You have toxic levels of vitamin D, which can be harmful to your health. You should take steps to lower your levels to below 100 ng/ml unless you’re under the supervision of your doctor.

To lower your levels, stop taking supplements. After three months, test your vitamin D levels and adjust the amount of supplement you take  once your test results show your level has dropped back down to the normal range.

References

  1. Bouillon, R. How to Define Optimal Vitamin D Status. In Vitamin D, Third Edition, by Feldman D, Pike JW and Adams JS. Elsevier Academic Press, 2011.
  2. Centers for Disease Control and Prevention. Second National Report on Biochemical Indicators of Diet and Nutrition, 2012.
  3. Garland CF, French CB, Baggerly LL, Heaney RP. Vitamin D supplement doses and serum 25-hydroxyvitamin D in the range associated with cancer prevention. Anticancer Res. 2011 Feb;31(2):607-11.
  4. Heaney, R. Assessing vitamin D status. Current Opinion in Clinical Nutrition and Metabolic Care, 2011.
  5. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM; Endocrine Society. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011 Jul;96(7):1911-30.
  6. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.
  7. Luxwolda MF, Kuipers RS, Kema IP, Janneke Dijck-Brouwer DA, Muskiet FA. Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. Br J Nutr. 2012 Jan 23:1-5.
  8. Smith MB et al. Vitamin D Excess Is Significantly Associated with Risk of Atrial Fibrillation. American Heart Assocation 2011 Meeting. 2011; 124: A14699.
  9. Vieth R. The Pharmacology of Vitamin D. In Vitamin D, Third Edition, by Feldman D, Pike JW and Adams JS. Elsevier Academic Press, 2011.
  10. Zhu K, Austin N, Devine A, Bruce D, Prince RL. A randomized controlled trial of the effects of vitamin D on muscle strength and mobility in older women with vitamin D insufficiency. J Am Geriatr Soc. 2010 Nov;58(11):2063-8.

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