What should your vitamin D levels be for optimum health?


What to do for chronically low vitamin D

What does vitamin D do for your body anyways?

Vitamin D is necessary for proper absorption of calcium and phosphorus from your foods, and ensuring that these minerals are properly incorporated into bone. 

A variety of studies show that sufficient vitamin D levels are associated with:

  • reduce inflammation in the gut among people with Celiac Disease
  • reduce the risk of flares of a number of autoimmune conditions including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and multiple sclerosis (MS)
  • lower blood pressure

It's a little bit of an unknown though... is low levels of vitamin D causing the inflammation during a flare-up or is it the result of the flare-up?

And, what's sufficient?

What is sufficient levels of vitamin D?

The standard "normal" range for vitamin D is between 20 and 50 ng/mL as tested in your blood and less than 12 ng/mL is considered deficient.

Like everything, ideally, you'd like for your vitamin D levels to be inside this range, preferably towards the middle of the range, so around 35 ng/mL or so, and this also varies depending on your skin color.  For darker skinned people, harm from vitamin D appears to occur at a lower vitamin D level than among lighter skinned people.

There's also extreme controversy around what sufficient levels are, and Dr. Michael Holick, a highly controversial figure in the vitamin D space, recommends higher levels.  While Dr. Holick's research in vitamin D is invaluable as he's credited with discovering many of the vitamin D metabolites and also piecing together the vitamin D pathway, this doctor's been

Too high vitamin D can result in decalcification of bones and lead to calcification of arteries and deposition of calcium in the soft tissues of the body. 

Cholecalciferol, also known as vitamin D3, the very same ingredient sold as vitamin D supplements is a common rat poison.  When rats eat too much vitamin D in the poison pellet, what kills them is essentially hypervitaminosis D or vitamin D toxicity, and the cause of death is typically bleeding out due to the extreme anti-coagulant nature of a hypervitaminosis D state.

Vitamin K, a vitamin you might not have heard much about, counters the anticoagulant effect of vitamin D and also encourages redeposition of calcium to bones (as opposed to soft tissues).

While today's conversation is intended to provide some insight into the controversy surrounding vitamin D, now's a great time to bring in nature's health.

Please do not use rat poisons.  Regardless of which type of rat poison you choose, creatures higher up the food chain, like birds of prey... including owls, suffer.  Coyotes also suffer.  Your dog that eats the poisoned dead rat while you're at work suffers.

Instead, for mouse and rat infestations, use one of these recommended deterrents and controls.

In humans, early symptoms of vitamin D toxicity include loss of appetite, nausea and vomiting, extreme thirst, weakness, nervousness, and eventually high blood pressure due to the calcium deposits within blood vessels.  These symptoms are synonymous with those of hypercalcemia because vitamin D toxicity encourages demineralization of bone and deposition of the calcium from bone in blood vessels.

Typically, you're only at risk for becoming vitamin D intoxicated when you're taking very high doses daily for months on end.  The recommended daily allowance (RDA) for vitamin D is 400 IU for children, 600 for adults, and 800 for people over 70.

There are some supplements as high as 10,000 IU, and it's at concentrations above this level daily that becomes potentially problematic with regards to acute toxicity.

The Merck Manual notes:

Taking very high daily doses of vitamin D—for example, 50 or more times the recommended daily allowance (RDA)—over several months can cause toxicity and a high calcium level in the blood (hypercalcemia).

As a general rule though, if you're taking significantly more vitamin D than the RDA and your vitamin D levels are still low, it's time to ask why this is.

Let's get into this part of the discussion with a quick overview of the vitamin D metabolic pathway.

Vitamin D Metabolic Pathway

In humans, 7-dehydrocholesterol present in the upper layers of your skin is converted to previtamin D3 in the presence of UVB rays from sunlight and then further converted in the lower layers of your skin to vitamin D3, also known as cholecalciferol.

Cholecalciferol (vitamin D3) is also the type of vitamin D present in food sources from animals while vitamin D2 (ergocalciferol) is the type present in plant sources of vitamin D in your diet.

Once the cholecalciferol is transported to your liver, your liver converts vitamin D3 into 25-hydroxyvitamin D3 (calcidiol).  25-hydroxyvitamin D3 is the circulating form of vitamin D in your body. 

25-hydroxyvitamin D3 is then further converted in your kidneys to 1 alpha, 25-dihydroxyvitamin D3 (calcitriol), which is the active form of vitamin D in your body.

Solubility of vitamin D metabolites in water

Regardless of its form, vitamin D is a fat soluble vitamin.  Vitamin D3 is the most fat soluble, so it has the lowest solubility in water at 0.02 micrograms per milliliter. 

The solubility of 25-hydroxyvitamin D3 is about 0.11 micrograms per milliliter or about 5 fold more soluble in water than vitamin D3.

The solubility of 1alpha, 25-hydroxyvitamin D3 is about 7 micrograms per milliliter or about 350 fold more soluble in water than vitamin D3.

To give you an idea of just how soluble that really is, the solubility of oil in water is about 100 micrograms per milliliter or about 14 fold more soluble in water than the active form of vitamin D (1 alpha, 25-hydroxyvitamin D3).

So, regardless of its form, vitamin D is not soluble in water.

Form of vitamin D in blood tests

25-hydroxyvitamin D, the circulating form of vitamin D, is measured on a blood test (calcidiol) rather than 1 alpha, 25-dihydroxyvitamin D, the active form of vitamin D. 

25-hydroxyvitamin D has a half life of about 15 days whereas calcitriol (1 alpha, 25-dihydroxyvitamin D) has a half life of about 5 to 8 hours. Why aren't calcitriol levels (1 alpha,25-dihydroxyvitamin D) checked on blood tests instead of 25-hydroxyvitamin D levels?  Great question.  I don't have the answer for that in today's episode.

Food sources of vitamin D

Cholecalciferol (vitamin D3) is what’s found in animal based foods and also the form of vitamin D most common in supplements. 

Natural vegan sources of vitamin D are hard to find.  And, while animal sources of vitamin D provide vitamin D3 (cholecalciferol), plant sources of vitamin D provide vitamin D2, also known as pre-vitamin D (ergocalciferol).

Mushrooms exposed to UV light while growing contain up to 1100 IU per 100 gram (3.5 ounce) serving and are one of the only plant sources containing significant levels of vitamin D.  The problem with mushrooms is that you often aren’t sure of whether they’re grown in light or dark conditions, and mushrooms grown in the dark don’t contain significant levels of vitamin D.

For vegans, ample sunlight or foods fortified with vitamin D are your best sources of this vitamin and one of the reasons for that is because vitamin D3 boosts your circulating level of 25-hydroxyvitamin D as compared with vitamin D2.  Commonly fortified foods include cereals, orange juice, and plant-based milks.

Dietary sources naturally rich in vitamin D include:

  • Cod liver oil (1360 IU in 1 Tbsp)
  • Sockeye salmon (815 IU in a 3.5 ounce serving)
  • Sardines (330 IU in a 3.5 ounce serving)

How much is enough sun exposure for vitamin D synthesis?

This depends on your age, your gender, your complexion, and where you live.  Your skin requires UVB, the type of UV rays most commonly blocked by sunscreen, to create vitamin D3 (cholecalciferol) from 7-dehydrocholeserol. 

Melanin reduces vitamin D conversion in your skin, so darker skinned people generally need to spend a little longer in sunlight each day to generate the same level of vitamin D3 as lighter skinned people.  How much does melanin influence your vitamin D conversion rate in skin?  One study found that melanin has an inhibition factor of about 1.4 for vitamin D3 conversion from 7-dehydrocholesterol.

Head to the references section below for the full pdf of this study.

Correctly applied sunscreen can reduce vitamin D creation by more than 90%.  And, because UVB rays are blocked by windows, you need to be outside to absorb those rays.

The good news is that your body self regulates so that you don't need to be concerned with generating too much vitamin D when you're out in sunlight for longer periods of time.

What conditions increase your risk of vitamin D deficiency?

  1. Those who follow a vegan diet.
  2. If you have inflammatory bowel disease (IBD), ulcerative colitis (UC), Crohn’s disease, or other conditions that disrupt normal fat digestion.
  3. If you’re obese. Vitamin D is fat soluble and can accumulate in fat tissue without being easily released later when it’s needed by the body.

Vitamin D deficiency is linked to chronic liver disease.  This is especially noteworthy because 25-hydroxyvitamin D (calcidiol), the vitamin D measured on a blood test, is synthesized in the liver.  In the liver, both vitamin D2 (plant based sources of vitamin D) and vitamin D3 (cholecalciferol) from animal based sources) or made by your body from sun exposure is converted into 25-hydroxyvitamin D. 

Low vitamin D levels and bone disease are well-recognized complications of cholestatic liver disease, which is any liver condition that causes impaired bile production, and may also be linked to a sluggish gallbladder or congested gallbladder.

Calcidiol (25-hydroxyvitamin D3) is available in 25 to 50 microgram capsules and may be prescribed or recommended for people with liver disease. 

Again, 25-hydroxyvitamin D3 is the circulating form of vitamin D3 and the active form, calcitriol (1 alpha, 25-dihydroxyvitamin D3) is also available but is associated with an increased risk of hypercalcemia and must be closely monitored.  

Calcitriol might only be recommended in those with severe kidney deficiency as the kidneys are responsible for the final conversion of circulating vitamin D to active vitamin D.

Why is it important that your liver converts vitamin D that you take in through food sources or that your skin creates from sunlight into the circulating form of vitamin D?

Have you ever had a blood test run for your vitamin D levels and they were either at the low end of normal or just outright low?

A few years ago in winter, I had my vitamin D levels checked and they were pretty good in the meaty middle of the range.  Then, a couple years later, my levels were checked again and they were low, touching the bottom of the normal range.

I was perplexed because it was summer and I was expecting my vitamin D level to be quite good.

This caused me to wonder whether there’s more to the story…

What if your levels of vitamin D3 + vitamin D2 are sufficient?

What if low vitamin D, which again is 25-hydroxyvitamin D3, the metabolite of vitamin D made by your liver, is a signal that your liver is struggling? 

Or, what if there's even more to the story?

Vitamin D is often low when your C-reactive protein levels are high.  CRP is typically high either when there's acute inflammation in your body such as when you're fighting off an infection and also in chronic inflammation such as autoimmune conditions and heart disease.

Low 25-hydroxyvitamin D might indicate you're fighting infection or stress or in a flare-up of an autoimmune condition.

One more possibility is this...

Could vitamin D deficiency be caused by a magnesium deficiency?

One more piece to this puzzle… the enzymes necessary for converting vitamin D3 + vitamin D2 to 25-hydroxyvitamin D3 in the liver and 1 alpha, 25 hydroxyvitamin D3 in the kidneys require magnesium.  And, magnesium deficiency is especially common in the population at large today due to depleted soils and depleted souls a stressful lifestyle including overexercising.

In fact, studies show improved response to vitamin D supplementation (with vitamin D3) when magnesium is also supplemented.  An NHANES study showed that high dietary intake of magnesium reduced the risks of vitamin D deficiency in the general population. 

Magnesium also plays a role in your body’s immunocompetence and adaptive immunity, and part of the reason for this is that magnesium influences the activity of vitamin D metabolites.

The RDA of magnesium for men is ~410 mg/day and for women ~315 mg/day. Studies estimate that food sources of magnesium range from 25% to 80% of what they were before 1950.  Nevertheless, here’s a list of a few foods and their magnesium content.

How much magnesium is in your food?

  • 1 ounce of pumpkin seed kernels contains ~168 mg magnesium
  • 1 ounce whole pumpkin seeds in shell ~74 mg
  • 1 ounce of dry roasted almonds ~80 mg
  • ½ c. boiled spinach ~78 mg
  • 1 ounce dry roasted cashews ~74 mg
  • ¼ c. oil roasted peanuts ~63 mg
  • ½ c. black beans ~60 mg
  • ½ c. shelled & cooked edamame ~50 mg
  • 1 ounce dark chocolate (60-69% cacoa) ~50 mg
  • 2 slices whole wheat bread ~46 mg
  • 1 c. avocado ~44 mg
  • ½ c. cooked brown rice ~42 mg
  • 1 c. plain low-fat yogurt ~42 mg
  • 1 c. milk ~25 mg
  • 3 ounces halibut ~24 mg
  • 3 ounces roasted chicken breast ~22 mg
  • 3 ounces ground beef (90% lean) ~20 mg

If you have low blood levels of vitamin D (measured as 25-hydroxyvitamin D3, the metabolite made by your liver), what have you been doing to boost your vitamin D levels?  If you answered:

  1. Spending more time in sunlight
  2. Adding a vitamin D supplement to your daily routine

has it been working? 

Are your vitamin D levels any higher now than when you made those changes? 

If you answered no, it may be time to consider:

  1. How's your stress level?
  2. Are you actively overcoming an infection of some sort or experiencing any allergies?
  3. Do you have an autoimmune condition, and if so, are you in a flare?
  4. What's your daily magnesium intake?

Boosting your magnesium reserves is an excellent way to help your body manage stress and inflammation, whatever the cause.  Great ways to boost your magnesium levels include:

  1. Adding more of the magnesium rich foods mentioned above into your diet
  2. Supplementing with a bioavailable form of magnesium like magnesium bisglycinate
  3. Adding an electrolyte mix to your water
  4. Soaking in Epsom salts. Yes, absorption of magnesium through your skin (transdermal absorption) helps boost your magnesium levels. The ability of magnesium to absorb into your skin has been demonstrated by a number of studies including two linked in today’s shownotes, one showing transdermal absorption of magnesium chloride and the second demonstrating transdermal absorption of magnesium sulfate, perhaps better known as Epsom salts.

Treat yourself to an aromatherapeutic Epsom salts soak with Rain Organica’s bath soaks.  Halcyon is naturally scented with lavender & chamomile buds and also includes ground chia seed to boost your skin’s moisture levels.  Zion bath soak is naturally scented with orange peels and rose petals.  Both bath soaks also make divine foot soaks and feature marshmallow root & licorice to soothe & nourish your skin.


https://foodb.ca/compounds/FDB021822 solubility of vitamin D in water






Magnesium sulfate reverses experimental delayed cerebral vasospasm after subarachnoid hemorrhage in rats.  Originally published1 Jul 1991. https://doi.org/10.1161/01.STR.22.7.922 Stroke. 1991;22:922–927








Brandy Searcy founder Rain Organica

About the Author

Brandy's a formulation scientist and self-proclaimed health geek who loves hiking, gardening, bird-watching, and body boarding. 

Her struggle with acne during her teens and 20s led to a holistic and healthy approach to skincare, embracing skin as an organ to be loved and cared for rather than a canvas to wage war on. 

Since 2008, she's been developing all-in-one products for a simple routine at home, & Rain Organica started when her backpacking friends asked for a portable skincare routine to keep their skin healthy & happy on and off the trails.

You can try Rain Organica for yourself with The Essentials Kit, a complete skincare routine in just 3 steps.

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