The Optimal Vitamin D Maintenance Dose

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Finding a regular dosage when you are no longer deficient

In the previous article, “The Holick Protocol,” we looked at the popular prescription–50,000 IU of vitamin D weekly for eight weeks–commonly prescribed to patients with a significant deficiency.

In this follow-up article we will look at the next step: the optimal maintenance dose. We will assume that the protocol was followed and the correction is complete, so the patient is ready for the regular dosage, also called a “maintenance dose.”

“My ‘number’ when diagnosed with breast cancer was a whopping low of 14,” says Karen Shackelford. “I was put on a protocol of 50,000 IU of vitamin D3 once a week for a month. Then I went to 10,000 IU for months. I was tested again and my number was between 40-60. Once I got over 60, I began taking 5000 IU and have been able to maintain at a preventative range of 70-90. I am currently at 84.”

Dr. Holick’s default follow-up dose after 50,000 IU once a week is 50,000 IU once every two weeks. Here is a review of data from medical records of his patients showing their progress:

Graph courtesy Dr. Holick

For the 45 patients who received only maintenance therapy of 50,000 IU of ergocalciferol every 2 weeks, the mean (SD) pretreatment 25(OH)D level was 26.9 (10.6) ng/mL, and the mean (SD) final level was 47.1 (18.0) ng/mL (P < .001) (Figure B).

Writes Dr. Holick in The Vitamin D Solution: “A few of my patients who had their first symptoms of multiple sclerosis and then were treated with 50,000 IU of vitamin D once a week for eight weeks and every other week thereafter, have remained in their honeymoon period.”

50,000 IU every 14 days averages 3,571 IU per day. Vitamin D supplements on the market now are typically available in individual capsules of 1000, 2000, 2500, 10,000 or 50,000. From different comments Dr. Holick has made, it appears the reason behind his choice of the 50,000 IU number is based on it being easier for patients to remember as opposed to a health benefit. (He once indicated there might actually be a slight advantage in taking a smaller D3 daily dose instead of a larger biweekly dose.)

Follow-up dosing scenario

In their article, “How much vitamin D should I take?,” two doctors in North Carolina, Dr. Colón-Emeric and Dr. Lyles, gave a case scenario; then asked for the correct decision.

The case was discussed and they concluded with their recommendations:

Given the relative safety of vitamin D within a wide serum range, the IOM recommendations appear overly cautious, and a higher dose of at least 1,000–1,200 IU daily appears prudent. For the patient described above, we would prescribe 50,000 IU D2 orally weekly for six weeks, followed by 2,000 IU D3 daily.[1]

Nurse practitioner

In another case, a nurse practitioner had a middle-aged female patient who had concluded her health problems “were simply the result of aging.” The practitioner described her testing and protocol decisions:

Having recently read about the increasing prevalence of vitamin D deficiency, I decided to
evaluate this patient’s vitamin D levels. Sure enough, they came back as 19 ng/ml…. I prescribed 50,000 u/day oral vitamin D3 once daily for eight weeks to begin repletion. Following this course, a repeat level will need to be assessed, and the patient will likely need to continue daily supplementation with 800 u/day.[2]

In both these examples the same Holick Protocol was followed for therapy, but they had different ideas on the follow-up for maintenance; i.e., 2000 IU and 800 IU, respectively.

Doctors who use the Holick Protocol may have higher standards than the IOM. The interesting thing is that some health practitioners want to use the Holick Protocol to resolve the deficiency, but then want to revert to the old IOM suggestion of 800-2000 IU daily, even though the IOM “raised their safe upper limit of daily intake for most age groups from 2,000 to 4,000 IU.”[3]

“A common problem arises from traditional medical training,” says Dr. Sarfraz Zaida, Assistant Clinical professor at UCLA and author of The Power of Vitamin D. “It teaches that once your Vitamin D stores are replenished, you go back to a daily maintenance dose of 400 IU a day.

“For example, if your Vitamin D is very low (let’s say less than 15 ng/ml), your physician will likely place you on a high dose of Vitamin D2 such as 50,000 IU a week for 12 weeks and afterwards, put you back on 400 IU a day as a maintenance dose.

“Most likely, in the following months, your physician won’t check to see what happens to your Vitamin D level on this miniscule dose. This kind of practice is based on the medical myth hammered into physicians that once you’ve replenished Vitamin D stores, the problem is somehow cured.

“Take a closer look at this myth. Vitamin D stays in your body stores for just a few weeks. Therefore, the “so called cure” of low Vitamin D will only last a few weeks and then you’ll be back to your usual state of a low level of Vitamin D.

“For this reason, I check Vitamin D level in my patients every three months. What I’ve discovered is eye opening! In my clinical experience, the maintenance dose of Vitamin D depends on the initial starting dose.

“For example, if a patient requires a high initial starting dose, that patient will need a high maintenance dose. Most people continue to require a high dose of Vitamin D to maintain a good level. It makes perfect sense. Why?

“It’s the overall lifestyle of a person that determines the level of Vitamin D. If a person is very low in Vitamin D to begin with, it’s due to life-style, which in most cases doesn’t change after a few weeks of Vitamin D therapy.

“Therefore, it’s important to continue a relatively high dose of Vitamin D as a maintenance dose, especially in those individuals who are very low in Vitamin D to start with.

“Most of my patients require a daily dose of 5,000-10,000 IU of Vitamin D3 to maintain a good level of Vitamin D. Some, especially obese individuals, need up to 20,000-25,000 I.U. a day, while some skinny individuals require only 2,000 IU per day.”[4]

“My multivitamin had 800 IU of vitamin D,” says Dr. Eric Madrid, “and my blood levels were deficient.”[5]

“After starting my patients on vitamin D2 supplementation,” he recalled, “I would wait three to four months before retesting their blood levels of vitamin D. I was shocked that [they had] barely budged. At the time I had tested over 20 patients with fibromyalgia and not one of them had a normal vitamin D blood level, that is, above 32 ng/ml (80 nmol/L).

“I waited another three months and then retested—the results were the same. They were still deficient. Most were on 2000 IU…. How could it be that they were still deficient? The recommended daily intake set by the government is obviously inadequate.”[6]

Dr. Rachel Corradetti, a naturopath in Canada, concurs.

“I can’t recommend doses,” she explains, “because I am not your naturopathic doctor. But I can tell you that Health Canada recommends between 400 IU to 800 IU per day based on your age and health status. In my experience, most of my patients are very deficient, and most require doses beyond 1000 IU in order to make any marked change and to get within sufficient levels.[7]

  1. Colón-Emeric, C. S., & Lyles, K. W. (2012). How much vitamin D should I take?. The Journal of clinical investigation, 122(5), 1598–1599.
  2. Leigh Montejo, “Detecting vitamin D insufficiency,” Mar. 21, 2012. [Nov. 2, 2021]. 
  3. How much vitamin D do you need?” Harvard Health, Jan. 31, 2019. [Nov. 2, 2021].
  4. Sarfraz Zaida, The Power of Vitamin D, 2010, p. 144.
  5. Eric Madrid, Vitamin D Prescription: The Healing Power of the Sun & How It Can Save Your Life, 2009, p. 34.
  6. Ibid, 22.
  7. Rachel Corradetti, “The Importance of Vitamin D,” May 19, 2020. http:/ [Nov. 3, 2021].

Pietras SM, Obayan BK, Cai MH, Holick MF. Vitamin D2 Treatment for Vitamin D Deficiency and Insufficiency for Up to 6 Years. Arch Intern Med. 2009;169(19):1806–1818. doi:10.1001/archinternmed.2009.361

Karen Shackelford, “What’s Your Vitamin D Number?” Apr. 14, 2021. [Nov. 5, 2021].

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