How Much Vitamin D3 Do You Need?

by Dr. Edward Group DC, NP, DACBN, DCBCN, DABFM Published on , Last Updated on

The most natural method for getting enough Vitamin D is through good ol’ sunshine.Vitamin D is a hot topic in the news these days and it’s also one of the most controversial subjects in medical research. The main debate centers around how much vitamin D3, a natural “nutrient” synthesized by the body in response to sunlight exposure, the average person needs. Governmental guidelines may be advocating for less-than-ideal vitamin D levels by giving a generalized recommendation for supplementation. It really is up to consumers to do the research to see how much vitamin D is really necessary.

Sources of Vitamin D

The most natural method for getting enough Vitamin D is through good ol’ sunshine. While sunshine may be best, those living farther from the equator or those who stay inside all day — especially in the autumn and winter months — will often experience a dramatic drop in vitamin D status. Glass windows, allow light to pass but can act as a barrier to UVB rays, the most beneficial rays for vitamin D synthesis. [1] [2] This is why supplementation is a must for most people.

What is the Best Amount of Vitamin D3?

When it comes to setting a uniform value for vitamin D, there are a few opinions. The Food and Nutrition Board (FNB) established the now common 400 IU (international units) per day standard; the Institute of Medicine recommends 600 IU per day. These values are said to help blood levels achieve 20 ng/mL and 30 ng/mL, respectively.

Other experts recommend 1,000-1,500 IU per day. [3] This typically generates a 60 ng/mL blood level. Even then, this may not be enough. An article in Osteoporosis International suggests 2,000-3,000 IUs be taken every day, especially by the elderly. [4] Some cases of vitamin D deficiency may require up to 10,000 IU per day. [5]

In our experience, 2,000 IUs per day seems to accommodate the needs of most people, especially when you’re taking a high quality vitamin D3 supplement like Suntrex D3.

Optimal Blood Levels of Vitamin D

With all the research into vitamin D and human health, it’s a wonder so many health organizations continue to disagree on the correct amount of D3 that should be circulating in your blood! On average, most believe a level between 40-80 ng/mL is suitable for most people. [6]

How Much Vitamin D is Too Much?

Vitamin D toxicity is rare but it can happen if you take extreme doses of vitamin D supplements. The biggest problem with vitamin D toxicity is an accumulation of calcium in your blood. This condition, known as hypercalcemia, can cause poor appetite, nausea, vomiting, weakness, and kidney problems. Taking 50,000 IU a day of vitamin D for several months has been shown to cause toxicity. This level is many times higher than any recommended allowance. Always talk to your doctor before taking extreme serving sizes beyond what’s recommended.

Testing for Vitamin D

How can we know what our Vitamin D status is at any given moment? Blood measurements. [7] This is the only sure method to assess Vitamin D levels with certainty. The blood marker to check for is called 25(OH)D, short for 25 hydroxyvitamin-D, and it ranges from 0 to 100 ng/mL (most people aim for a number somewhere in the high middle).

Bottom Line

Fortunately, as Vitamin D awareness and importance has grown, getting your blood tested is becoming a far more common request and it’s not uncommon for insurance to cover it. Based on the research, investigations, and extensive experience of the aforementioned experts in the field, a safe, somewhat general recommendation is to consume between 2,000 IU to ­4,000 IU/day (3,000 IU/day avg.) of Vitamin D3 (cholecalciferol). To ensure optimal supplementation, look into getting tested for 25(OH)D.

Have you had your vitamin D levels tested? Leave a comment and tell us about your experience!

References (7)
  1. Tuchinda C, Srivannaboon S, Lim HW. Photoprotection by window glass, automobile glass, and sunglasses. J Am Acad Dermatol. 2006 May;54(5):845-54.
  2. Kumaravel Rajakumar, MD, Susan L. Greenspan, MD, [...], and Michael F. Holick, MD, PhD. SOLAR Ultraviolet Radiation AND Vitamin D. Am J Public Health. 2007 October; 97(10): 1746-1754.
  3. Heike A Bischoff ­Ferrari, Edward Giovannucci, Walter C Willett, Thomas Dietrich, Bess Dawson­ Hughes.Estimation of optimal serum concentrations of 25­hydrox. Am J Clin Nutr July 2006 vol. 84 no. 1 18­28.
  4. Leidig-Bruckner G, Roth HJ, Bruckner T, Lorenz A, Raue F, Frank-Raue K. Are commonly recommended dosages for vitamin D supplementation too low? Vitamin D status and effects of supplementation on serum 25-hydroxyvitamin D levels--an observational study during clinical practice conditions. Osteoporos Int. 2011 Jan;22(1):231-40. doi: 10.1007/s00198-010-1214-5.
  5. Amir E, Simmons CE, Freedman OC, Dranitsaris G, Cole DE, Vieth R, Ooi WS, Clemons M. A phase 2 trial exploring the effects of high-dose (10,000 IU/day) vitamin D(3) in breast cancer patients with bone metastases. Cancer. 2010 Jan 15;116(2):284-91. doi: 10.1002/cncr.24749.
  6. Vitamin D Council. For health professionals: Position statement on supplementation, blood levels and sun exposure. Vitamin D Council Fact Sheet.
  7. Kurt A. Kennel, MD, Matthew T. Drake, MD, PhD, and Daniel L. Hurley, MD. Vitamin D Deficiency in Adults: When to Test and How to Treat. Mayo Clin Proc. Aug 2010; 85(8): 752-758.

†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. Global Healing Center does not dispense medical advice, prescribe, or diagnose illness. The views and nutritional advice expressed by Global Healing Center are not intended to be a substitute for conventional medical service. If you have a severe medical condition or health concern, see your physician.

  • Price Weston

    Getting 400-600 IU of vitamin D from food is not an easy task. While producing your own vitamin D (sulfite) from sun exposure is highly variable (latitude, youthfulness, obesity, skin pigmentation, time of day, season, etc), the amount of vitamin D produced exceeds the RDA by 10s of thousands of percent. All the benefits of a walk in the sun from lower blood pressure to mental state improvements are not achieved by taking supplemental vitamin D. That being said, we are not hunter gatherers anymore.

    It took my wife 5000 IU of D3/day to get to 60 ng/mL and it took me 13,000 IU/day for many many months to get there. There is a rule of thumb and that is if you are of healthy weight (BMI below 25), it takes 1000 IU of D3/day to raise your blood levels by 10 ng/mL. If you are overweight or obese, it takes much more. Given that the half life is about 3 weeks, it takes many months to see the full effect of consistent daily supplementation. I guesstimated that adding 3 weeks of daily supplementation to the first couple of days of your daily amount will jump start your blood levels to where it would normally take many months.

  • Bethany

    Thank you for sharing. I appreciate your knowledge.

  • knowing that the chemtrails knock out 90% of the sunlight … I take 5,000 IU’s of vitamin D a day… many do not believe in chemtrails…and do not up their dosage… why cancer rates are 1 in 2 now… vitamin D deficiency = cancer

  • Adam

    I take 10000 iu a day bc I read that 8000 iu increases serotonin levels. Make sure you take your k2 with your d3. One thing I’ve had trouble finding out is the correct amount of k2 to take with the d3. Apparently if you take the d3 alone, it will not be absorbed in your body that well.

  • Virginia Cochrane

    I tried doing 4000 IU of vitamin D3 and found that I got headaches and felt quite sleepy in the middle of the day. Was this due to the vitamin D3 or was it something else? I discontinued and the headaches went away after about a week. I started up again at 2000 IU every second day. No headaches and not sleepy come lunch time. Does this mean that I have found the right dosage for me? Or should I have just kept up with the 4000 IU and maybe the headaches and feeling sleepy would have eventually went away. Does the body need to get used to the right dosage? I would like to answers to these questions, if you can. My e-mail address is ;

  • uptotrix

    Do not take it on an empty stomach, take it just after you finish your lunch. Otherwise your intestines will have a hard-time absorbing it. The problem is human body will reject anything that is new and foreign…just like when you were a kid you had a hard time getting used to different foods. So that’s why you must slowly raise the dose to avoid the many of these side effects. I advice you follow the same method for every vitamin.

  • Darlene Renee Whittiker-Harris

    I just got a new doctor, and was told my vitamin B level was low, and was prescribed vitamin D from the pharmacy 50,000 IU D2 (Ergo) gelcaps. However when I read the side affects I must say, it was frightening to read the ‘possible side affects’. The dosage is take 1 per week for 3 months and it should raise my D level. I take medication for blood pressure amlodophine, 2 cod liver oil gel capsules daily, liquid geritol daily dose, an herb for boils that I used to get under my arms called Freedom from New Body products which has the ingredients of Golden Seal Root, Dandelion Root, Burdock Root, Yellow Dock Root, Capsicum, and Garlic. I also take another herb called CKLS which stands for Colon, Kidney, Liver and Spleen which has the ingredients of Aloe Vera Resin, Chamomile, Caseara, Sagrada, Chapparal Mullein, Uva Ursi, Fenugreek, Cayenne, Dandelion, and Eucalyptus. When I read that Vitamin D is better if you get plenty of sunlight daily at least 5 to 10 minutes daily will raise your vitamin D levels tremendously and it is also a better form of vitamin D due to the sunlight. I don’t want to take medication if a vitamin supplement, herb or sunlight will help just as much or more. Please give me your opinion on this. Thank you kindly.

  • Marcus Opus Morgan

    I agree !!!

  • Cheryle

    I am an active, 56 year old, 4 hours of daily sun exposure, bmi 23, lactose intolerant (so, no dairy = no typical calcium foods), daily vitamin & mineral supplementation. Blood tests revealed blood calcium level as high ‘normal’, D level low ‘normal’. Concerned about bone loss, I researched causes that revealed possible parathyroid tumor. I took my concerns to my primary physician, who laughed it off and told me I was in ‘normal’ ranges and “I had nothing to worry about”. Not convinced, I went to a different physician for a second opinion: re-tested D & calcium; tests revealed D lower & blood calcium higher; and was told to limit calcium intake to no more than 1 glass of milk daily (remember, I can’t consume dairy) and bump up D to 2000 iu daily, but that I was “… within normal ranges and had nothing to worry about.” Still not convinced and still concerned the calcium in my blood was being leached from my bones, I sent all test results to the Norman Parathyroid Institute in Florida for review. In the meantime, I went to a third physician, my ob/gyn, requesting a dexa scan to check my bones. Again, with a grin on his face I was told that I “had nothing to worry about”, but a dexa scan was ordered to “ease my mind”. I week later, received a phone call from a physician at Norman Parathyroid Institute confirming I had a parathyroid tumor that MUST be removed, and surgery was scheduled. A few days later my concerns were confirmed when I received a phone call from the 3rd physician confirming osteopenia and an urgent need to have drug intervention treatment! Physician recommendations very likely would have caused a stroke and/or death! Instead, I flew to Florida where, during an 18 minute surgery, had 1 parathyroid tumor removed and other 3 deemed perfectly healthy. Prognosis is full replacement of calcium loss due to tumor with good quality daily Calcium and Vit D supplementation. Long story short: ‘normal’ levels outdated (last reviewed in 1960’s) especially in the US; really look at your test results; be your own health care advocate and research anything you don’t understand; and, seek out and follow sites like Global Healing Center to educate yourself! Do not simply hand over your health to someone else! Latest stats show at least 40% of our population is Vit D deficient, but the actual percentage is likely even higher!

  • Tannim

    180 mcg of K2 per 5000IU of D3

  • Jonna Lemmon

    My level is 19! How much should I take a day?

  • Mateelyah Mahmoud Sousa

    38 years old, female,
    I had mines tested and the level is 12.4, extremely low. It didn’t appear to be of great concern to the Dr. She prescribed vitamin D2, however after researching I’m placing myself on D3. I took 1 pill oder D2 yesterday of 50,000. I’m wondering do I need to allow this to work into my system before taking D3? Also can the pharmacist advise on how much D3 I should take?

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