What Do You Know About (Hormone) Vitamin D?

Most everybody knows that we get vitamin (hormone) D from the sun. You can learn more about this process in “How Do We Make Vitamin D In Our Body?” What we want to focus on today is what form is best and is it good to supplement vitamin D3?

Did you know there are 7 forms of hormone (vitamin) D or calciferol?

[Frontiers in Bioscience 9, 3007-3018, September 1, 2004]

Most of us are only familiar with vitamin D2 and vitamin D3, perhaps D3 more so. Vitamin D2 is what many doctors give by injection which is a synthetic form referred to as ergocalciferol which should be avoided. (1)(2)(3) Vitamin D2 is also found in some foods like mushrooms. Some supplement producers ignorantly and mistakenly irradiate mushrooms believing they are increasing the D2 content. But one can get D2 from plants. D3 (cholecalciferol) can be found in mammals and fish so it is possible to get D3 from fish oils such as cod liver oil and others. D3 is also made in sheep’s skin and obtained from lanolin which is made from the sheep’s wool.

Many people, because hormone D3 is listed as a vitamin, don’t keep in mind that this is actually a hormone. Many take huge amounts of supplemented vitamin D. Who in their right mind, would knowingly take a hormone in such excess? Yet even some doctors have prescribed from tens of thousands to a hundred thousand units when only 600 units (800 I.U ages 70+) have been established as an appropriate dose. Yet, I’ve spoken with many who’ve been prescribed from 50,000 to 100,000 I.U. of vitamin D3 (usually weekly). Many have been told by their doctors to take 10,000 units a day. This has often caused issues aside from Hypervitaminosis D, with hypercalcemia (excess calcium in the blood) because D3 increases calcium absorption. If this hormone is obtained naturally, this can be a good thing for someone who has low calcium or those who need calcium for osteoporotic conditions of the bones. But too much calcium can cause heart attacks as calcification occurs in the blood vessels and heart or other organs. It can cause decreased stomach acid because calcium is an alkaline mineral, thus neutralizing stomach acid, leading to digestive disorders. Additionally, it can cause kidney stone formation in the form of calcium/oxalate stones which can lead to kidney damage, and also constipation. But the supplementation of hormone D3 has caused even healthy people to lose bone density. Although there was not much loss of over-all bone strength, a recent study showed a 1.2% negative increase in bone density with only 400 I.U. of supplemented D3. That may not seem very significant and isn’t to most healthy people, though it may be more so later in life when density tends to decrease anyway. But that wasn’t the whole of it. It was also found a 4,000 I.U. dose of hormone D3 caused a -2.4% increase and 10,000 unit dose caused -3.5% increase. This means the higher the dose, the more bone density was lost. Further, this was with healthy people who did not already have bone loss such as those with Osteoporosis, which may increase that factor.

This was offered by APhA

“Our study showed that for healthy, vitamin D–sufficient adults, there is no evidence of further bone benefit in pushing the dose of vitamin D any higher [than the recommended dose]. There may even be a potential for harm to the skeleton,” said coprincipal investigator David A. Hanley, MD, FRCPC, professor emeritus of medicine, community health sciences, and oncology at the University of Calgary in Alberta, Canada.

In this 3-year, double-blind, randomized clinical trial, Canadian researchers studied the effects of different daily doses of vitamin D3 on bone health in 311 community-dwelling healthy adults with normal baseline levels of vitamin D and without osteoporosis. The study participants, who were aged 55 to 70 years, 53% male, and 95% white, were randomly assigned to receive 400 IU, 4,000 IU, or 10,000 IU of vitamin D3 supplements every day from August 2013 to December 2017 in addition to the estimated 200 IU they consumed from their daily diet.

While a small degree of BMD loss is normal for the age group studied, by the end of the study, radius volumetric BMD significantly decreased by 2.4% and 3.5% among those treated with 4,000 and 10,000 IU per day of vitamin D3, respectively, compared with a 1.2% decrease in those who received 400 IU per day. Tibial volumetric BMD also significantly decreased by 1.7% among those assigned to the 10,000 IU group.

In other words, patients given high doses of vitamin D3 experienced greater bone loss than those who received a modest dose.

American Pharmacits Association “Too much vitamin D may cause bone harm, study finds”

One article by Science Alert said:

The results showed no association between vitamin D levels over a lifetime and the risk of fracture. This latest study contradicts the UK government’s recent view, but not a host of earlier clinical trials.

In 2014, a review and meta-analysis of 31 vitamin D supplement trials found no effect on all fractures. Much of our strong belief in the benefits of vitamin D came from studies of supplements in care homes in the 1980s, which were never replicated and were probably flawed.”

Science Alert “The Largest Ever Clinical Study on Vitamin D Shows We’re Wrong About One of Its Main Benefits

It went on to say,

In a more recent meta-analysis of 33 randomised trials of over 50,000 older adults, supplementation with calcium or vitamin D had no effect on the incidence of fractures. There were also no clear benefits on muscle strength or mobility.

So, if all the data points to vitamin D failing to prevent fractures, why worry about all the people with low blood levels of the vitamin?

Science Alert “The Largest Ever Clinical Study on Vitamin D Shows We’re Wrong About One of Its Main Benefits

For decades, vitamin D3 has been prescribed and suggested by doctors who are ignorant of many things regarding nutrition and D3 has been taken for as long by those who also have had no clue about it’s effects in large doses. Most of these have had no idea that taking it also hinders the conversion of 7-Dehydrocholesterol in the skin to the precursor or pro-vitamin D3. It fools the body into thinking it’s getting more sun and being warmer.

One of the leading physicians in this field is Dr. Pamela Popper who offers the following explanation and results of some recent studies on this bone-density loss which follows:

But Dr. Popper is not the only one on this band-wagon and bone density loss is not the only negative side effect of D3 supplementation. This article from Endocrinology Today also gives evidence of bone loss. This was also supported by the American Pharmacists Association in their article.

But bone density is not the only issue with hormone D3 supplementation. Consumer Labs, that conducts studies on various nutrients/supplements has this to say about too much D3.

The idea has been suggested that adverse effects of very high doses of vitamin D can be eliminated by also administering doses of vitamins A and K. This has not been proven and remains only a hypotheses put forward by an individual, as noted in the How Much Do You Need and How Much Is Too Much? section of the Vitamin D Supplements Review.

Getting too much vitamin D may have harmful effects, such as increasing the risk of fractures and falls and upper respiratory infections, interfering with sleep (apparently due to reduced production of melatonin), and hypercalcemia (too much calcium in the blood, causing a variety of symptoms). For more about this, the Concerns and Cautions section of the Vitamin D Supplements Review.

Tod Cooperman, M.D. – Consumer Labs “Preventing Too Much Vitamin D by Taking Other Vitamins” (Last Update: 9/18/2019)

One last thing on applications to Osteoporosis, is vitamin D supplementation may not give as much benefit to the condition as many have believed. Although the presence of vitamin D is needed and does offer immense benefit in treating Osteoporosis, “in a more recent meta-analysis of 33 randomised trials of over 50,000 older adults, supplementation with calcium or vitamin D had no effect on the incidence of fractures. There were also no clear benefits on muscle strength or mobility.” (4)

There’s more! Chris Kresser M.S. says, “Healthcare practitioners are increasingly aware of the risks of low vitamin D levels, but many are not aware that high levels of vitamin D can have toxic” effects. (5)

Vitamin D status is measured by 25(OH)D in blood. We’ll dive further into vitamin D metabolism later, but for now, just understand that this is the precursor to active vitamin D and is generally considered the most accurate single marker to assess vitamin D status. The U.S. laboratory reference range for adequate 25(OH)D is 30 to 74 ng/mL, while the Vitamin D Council suggests a higher range of 40 to 80 ng/mL, with a target of 50 ng/mL.


Chris goes on to say,

But a large body of evidence in the medical literature strongly suggests that optimal vitamin D levels might be lower than these figures. There is little to no evidence showing benefit to 25(OH)D levels above 50 ng/mL, and increasing evidence to suggest that levels of this magnitude may cause harm. Consequences of vitamin D toxicity include heart attack, stroke, kidney stones, headache, nausea, vomiting, diarrhea, anorexia, weight loss, and low bone density (6).

Chris Kresser “Vitamin D: More Is Not Better June 12, 2019

He added, “Ethnicity is one major consideration. For example, black people have lower 25(OH)D than white people in the U.S., yet they typically have much higher bone mineral density. Furthermore, non-Caucasians have lower 25(OH)D levels than Caucasians, even at their ancestral latitudes (7). From these and other studies, it has been suggested that people with non-white ancestry may be adapted to a lower optimal 25(OH)D level than people with white ancestry.”

A study on traditionally living hunter–gatherer populations in East Africa found that the Masai and Hadzabe tribes had average 25(OH)D concentrations of 48 ng/mL and 44 ng/mL, respectively. (8) These indigenous populations get a great deal of sun exposure but also have very high intakes of vitamins A and K, suggesting that these levels are probably towards the higher end of the optimal range for most people in the modern world. (9)

Finally, Chris adds this:

Based on my assessment of the literature and my own clinical experience, I believe the functional range for 25(OH)D is around 35 to 60 ng/mL. However, I can’t stress enough that there is significant variation among populations. For those with non-white ancestry, the optimal range may be a bit lower. For those with autoimmune disease, the optimal range might be a bit higher (45 to 60 ng/mL) to maximize the immune-regulating benefits of vitamin D. Here are a few recommendations for optimizing your vitamin D level.

  1. Don’t supplement blindly.
    If your 25(OH)D level is:
  • less than 20 ng/mL: you likely need some combination of UV exposure, cod liver oil, and a vitamin D supplement
  • 20 to 35 ng/mL: get your PTH tested. If PTH is adequately suppressed (less than 30 pg/mL), supplementing is probably unnecessary.
  • 35 to 50 ng/mL: continue your current diet and lifestyle for maintaining adequate vitamin D
  • greater than 50 ng/mL: try reducing your vitamin D supplements, and make sure you are getting adequate amounts of the other fat-soluble vitamins to protect against toxicity (9)
Vitamin D Optimal Levels

In light of so much evidence that too much is not good and that supplementing either D2 is not good, this leaves sunshine and food. Dr. Chris Masterjohn, nutritional biochemist says you should spend the first five minutes in the sun with no protection (sunscreen) and that in the time it takes to begin to burn, one would get up to 25,000 I.U. of (precursor /pro-vitamin D3) (Vitamins & Minerals 101 by Chris Masterjohn)

So what foods naturally have vitamin D?

“Beef liver, cheese, egg yolks, and fatty fish, which contain small amounts of D3. Cod liver oil is also a great source. One teaspoon contains about 450 international units of vitamin D3. Other fish sources are rainbow trout, swordfish, sturgeon, cisco, whitefish, mackerel, tuna, halibut, herring, and rock fish. Mushrooms have vitamin D2. Portabello mushrooms have as much as 320 grams of vitamin D2. Shiitake mushrooms also have D2. (20)(32)(33) There are also many spices and herbs that have vitamin D.” (10)(11)

Here’s something else that you may want to be aware of about vitamin D. There are a number of factors that can affect your absorption. One not covered in the following linked article, is the more you supplement, the less you can get from the sun. I’m looking for that piece but for now, you may want to know about these:

1. The latitude where you live. At higher latitudes, the amount of vitamin D–producing UVB light reaching the earth’s surface goes down in the winter because of the low angle of the sun. In Boston, for example, little if any of the vitamin is produced in people’s skin tissue from November through February. Short days and clothing that covers legs and arms also limit UVB exposure.

2. The air pollution where you live. Carbon particulates in the air from the burning of fossil fuels, wood, and other materials scatter and absorb UVB rays. Ozone absorbs UVB radiation, so holes in the ozone layer could be a pollution problem that winds up enhancing vitamin D levels.

3. Your use of sunscreen — in theory. Sunscreen prevents sunburn by blocking UVB light, so theoretically, sunscreen use lowers vitamin D levels. But as a practical matter, very few people put on enough sunscreen to block all UVB light, or they use sunscreen irregularly, so sunscreen’s effects on our vitamin D levels might not be that important. An Australian study that’s often cited showed no difference in vitamin D between adults randomly assigned to use sunscreen one summer and those assigned a placebo cream.

4. The color of your skin. Melanin is the substance in skin that makes it dark. It “competes” for UVB with the substance in the skin that kick-starts the body’s vitamin D production. As a result, dark-skinned people tend to require more UVB exposure than light-skinned people to generate the same amount of vitamin D.

5. The temperature of your skin. Warm skin is a more efficient producer of vitamin D than cool skin. So, on a sunny, hot summer day, you’ll make more vitamin D than on a cool one.

6. Your weight. Fat tissue sops up vitamin D, so it’s been proposed that it might be a vitamin D rainy-day fund: a source of the vitamin when intake is low or production is reduced. But studies have also shown that being obese is correlated with low vitamin D levels and that being overweight may affect the bioavailability of vitamin D.

7. Your age. Compared with younger people, older people have lower levels of the substance in the skin that UVB light converts into the vitamin D precursor, and there’s experimental evidence that older people are less efficient vitamin D producers than younger people. Yet the National Center for Health Statistics data on vitamin D levels fly in the face of the conventional wisdom that vitamin D inadequacy is a big problem among older people. They don’t show a major drop-off in levels between middle-aged people and older folks.

8. The health of your gut. The vitamin D that is consumed in food or as a supplement is absorbed in the part of the small intestine immediately downstream from the stomach. Stomach juices, pancreatic secretions, bile from the liver, the integrity of the wall of the intestine — they all have some influence on how much of the vitamin is absorbed. Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn’s disease, and cystic fibrosis, can reduce vitamin D absorption.

9. The health of your liver and kidneys. Some types of liver disease can reduce absorption of vitamin D because the ailing liver isn’t producing normal amounts of bile. With other types, steps essential to vitamin D metabolism can’t occur — or occur incompletely. Levels of the bioactive form of vitamin D tend to track with the health of the kidneys, so in someone with kidney disease, bioactive vitamin D levels decrease as the disease gets worse, and in end-stage kidney disease, the level is undetectable. (12)

One last thing about taking hormone D3, you need to match it with vitamin K2 @ 100 mcg. for every 1000 units of D3 taken or you increase the risk of heart attacks, kidney stones and kidney damage, and other health issues. (10)

It would appear that with new information on hormone D3, we need to ease up on supplementing and especially with excess dosing.

To Your Health!

Written by Douglas K. Johnson – Life, Health and Wellness Coach, Herbalist, Nutritionist, and Author

Medical Disclaimer

This blog pro­vides gen­eral infor­ma­tion and dis­cus­sion about med­i­cine, health and related sub­jects.  The words and other con­tent pro­vided in this blog, and in any linked mate­ri­als, are not intended and should not be con­strued as med­ical advice. 

If the reader or any other per­son has a med­ical con­cern, he or she should con­sult with an appropriately-licensed physi­cian or other health care worker.

Never dis­re­gard pro­fes­sional med­ical advice or delay in seek­ing it because of some­thing you have read on this blog or in any linked materials. If you think you may have a med­ical emer­gency, call your doc­tor or 911 immediately.

The views expressed on this blog and web­site have no rela­tion to those of any academic, hospital, practice or other insti­tu­tion with which the authors are affiliated.

Published by Douglas Johnson

I am a Life, Health and Wellness Coach, Herbalist, Nutritionist, Author & Chef

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