Vitamin D₃ Quick Reference

Page edition: 2024-05-13
Note: although this basenote is publicly-visible, some links and responses may be IC members-only.

⟲ Context

Vitamin D is a core program supplement. Unless you are under 40, live near the equator, spend most of your daytime outdoors, year-round, with extensive skin exposure (i.e. live an ancestral lifestyle), your vitamin D levels are very likely suboptimal.

⟲ Contents

⟲ General Information

The need for vitamin D has been part of the program, going back at least a decade, and is extensively discussed in these books and program materials (page numbers shown for U.S. print editions):
📖 Wheat Belly Total Health (2014): page 175
📖 Undoctored (2017) page 272
📖 Wheat Belly Revised & Expanded (2019) page 243
📖 Super Gut (2022) page 160
🖵🗏 The Crucial Role of Vitamin D (members)
🅑 WBB: Autoimmune diseases and vitamin D (members)
🅑 WBB: Vitamin D: Get the timing right (members)
🅑 WBB: 10 Things You Probably Didn’t Know About Vitamin D: Essential Info During a Pandemic (members)
🅑 WBB: Vitamin D: What is the best form? (members)
🅑 WBB: Vitamin D and Immunity (members)
🅑 WBB: Why sun exposure may NOT be a reliable way to obtain vitamin D (public)
🅑 WBB: Common misconceptions surrounding vitamin D (public)
🅑 WBB: What are the symptoms of vitamin D deficiency? (public)
🅑 WBB: Ten rules to get your vitamin D just right (public)
🅑 WBB: How important is Vitamin D? (public)
🅑 WBB: DIY vitamin D (public)
🅑 WBB: Is Vitamin D Deficiency the Rule, rather Than the Exception? (public)⇱ Return to ToC

⟲ Program Vitamin D Target

Program target is based on a periodic blood test; a 25-hydroxy vitamin D level of:
  60 to 70 ng/mL (150-180 nmol/L)
See ⇩Testing considerations below for more information.
Note that consensus nutrition is only slowly catching up. The program’s lower limit usually requires Vitamin D intake well above common official guidelines. Although the guidelines doubled a few years ago, from 10µg (400 IU) to 20µg (800 IU), they are still usually sub-optimal.
Note also that FDA labelling standards shifted from IU to µg (mcg) in 2020.

The program target usually requires a vitamin D supplement, often in the range 150 µg±100µg (6000 IU±4000 IU). This is about 7.5× common RDAs. Another rule of thumb for a starting portion is 1µg (40 IU) per pound of body weight, or 2.2µg (88 IU) per kg.

Individual requirements vary with age, situation and season, so getting tested is strongly encouraged.⇱ Return to ToC

⟲ Cautions

Response to vitamin D is an inverted U-curve ∩, with benefits dropping off above and below target titer. This is why testing is needed to determine what’s optimal for you.

At extremely high values, there is some risk of Hypervitaminosis D. Supplementation above 250 µg (10,000 IU) is not something to guess at. That said, people starting the program with a high BMI are apt to need more D₃ to hit program 25OH-D3 target, and then less over time as weight is lost.

Vitamin D supplementation may be contraindicated in granulomatous disorders, such as sarcoidosis.

Tanning salons may be completely ineffective at stimulating vitamin D.⇱ Return to ToC

⟲ Supplement considerations

⟲ Supplement form

The molecular form of vitamin D to supplement is D₃ (cholecalciferol), and not D₂ (ergocalciferol).

The supplement formulation to use is oil-based (and not dry, such as tablet). Gel caps are fine, as are liquid drops. Don’t worry about any incidental D₃ in any tablets you might be taking, but also don’t expect it to be well absorbed Again, testing settles this question.

Thousands of IUs are still just low hundreds of micrograms (µg) of actual D₃, so the overall product formulation must be carefully considered

Store your D₃ supplement out of sunlight. Refrigeration is fine.

⟲ Portion timing

Take D₃ supplements early in the morning, to mimic the circadian effect of sunlight. Avoid taking D₃ in the evening or at night, as it may disrupt sleep.

Depending on your situation, seasonal dose adjustment could be appropriate:
🖵🗏 Should I Take Vitamin D Year Round? (members)

⟲ Portion adjustment

The general rule of thumb for D₃ supplementation adjustment is:
  2.5 µg/ng/ml (1 µg/nmol/L)
  100 IU/ng/ml (40 IU/nmol/L)
So if your 25OH test came back at 40 ng/ml at the start of your program, and using the middle of the target range ((60+70)÷2)=65 as a goal, you might increase your vitamin D supplementation by:
  2.5×(65-40) = +62.5 µg
  100×(65-40) = +2500 IU

See Testing for more information on dose adjustment.⇱ Return to ToC

⟲ Supplement suggestions

For the cautious buyer, subscription site /℄\ConsumerLab.com periodically tests Vitamin D supplements.

Check ingredients. In a stand-alone D₃ gelcap, coconut, or MCT oil are fine. While a credible olive oil would be acceptable, the problem is the ‘credible’ bit. A high-oleic sunflower or safflower oil might be a safer bet. Junk oils like soybean, corn, peanut (or other grain or legume) are distressingly common in oil-based products, and indicate formulators who are either clueless, or not terribly concerned about your health. Entirely avoid relying on tablets and dry capsules (absorption issue). Most vitamin D liquid (drop) product are fine, if they use otherwise acceptable ingredients.

Because fish oil is also a core supplement in the program, using a fish oil product that contains D₃ is an interesting option. This normally means having two forms of that fish oil on hand, one with D₃, and the other without, due both to dose ratios, and wanting to spread the fish oil across the day. These two Sam’s Club Members Mark products may work for you:
⎆600mg Omega-3 from Fish Oil with 50 mcg Vitamin D3 Softgels
(540 mg DHA+EPA, 2000 IU D₃ per capsule)
⎆Triple Strength Fish Oil Softgels
(900 mg DHA+EPA per capsule)
Similar products may be available from
⎆Nordic Naturals
(275mg EPA+HDA, 12.5µg/500 IU D₃ per softgel).⇱ Return to ToC

⟲ Testing considerations

⟲ Test details

If this test isn’t routinely covered by your carrier, it’s often cheaper to obtain it on your own, nanny state permitting, from a walk-in lab, perhaps via a Life⌬Extension order, or via a home 🌢ZRT Test Kit.
Self-directed price range: US$30.00-83.00

⟲ Test day considerations

Fasting status: It is not necessary to test D₃ fasting.
Day’s D supplement: may be taken before or after draw
Time of day for test: anytime

⟲ Re-Test timing

After a supplement dose adjustment, wait ⎆at least 21 days before re-test. Re-testing every 2-3 years is reasonable.⇱ Return to ToC