How much vitamin D3 to take?

It depends on body weight and obesity status.

These average daily supplemental vitamin D3 intake quantities, as ratios of body weight, in kilograms:

• 70 to 90 IU / kg for those not suffering from obesity (BMI < 30).

• 100 to 130 IU / kg for obesity I & II (BMI 30 to 39).

• 140 to 180 IU / kg for obesity III (BMI > 39).

are the recommendation of New Jersey based Professor of Medicine Sunil Wimalawansa (CV).

[Please see the 2024-03-13 update at the end of this article.]

For 70 kg (154 lb) without obesity, this is 4900 to 6300 IU per day, on average.

“IU” is short for the grandly titled unit "International Unit”, which for vitamin D3 is a very small quantity - 1/40,000,000th of a gram. It is a great misfortune that the mass of an IU of vitamin D3 was set so low - to about the amount a baby rat needs each day to avoid developing the weak limb bones of rickets.

It can be difficult for some people to believe they need 5000 of anything each day to be healthy, especially in Australia and some other countries where the greatest capacity vitamin D3 tablets or capsules available without prescription (or after consulting a naturopath) is the still impressive sounding amount of 1000 IU (0.25 milligrams = 25 micrograms.

However, 5000 IU a day is a very small amount:

• 125 micrograms (mcg = millionths of a gram) per day.

• 0.125 milligrams (mg = thousandths of a gram) per day.

• One gram every 22 years. (Pharma grade vitamin D3 costs about USD$2.50 a gram, ex-factory.)

The three ranges of ratios of body weight above are Prof. Wimalawansa’s slight simplification, presented in an FLCCC webinar in August 2023, of somewhat more complex recommendations in his July 2022 article in Nutrients:

Rapidly Increasing Serum 25(OH)D Boosts the Immune System, against Infections - Sepsis and COVID-19
Sunil J. Wimalawansa  Nutrients 2022-07-21 www.mdpi.com/2072-6643/14/14/2997.

The recommendations apply to people of all ages, body weights and body types, unless they have received medical advice to the contrary.

From babies to the elderly - whether underweight, normal weight or overweight - the first range of ratios applies. In different units, this is, on average, per day:

• 70 to 90 IU / kg.

• 32 to 41 IU / pound.

• 0.8 to 1.0 mcg (micrograms) / kg.

The green band in the graph above depicts this range of ratios.

Vitamin D3 cholecalciferol:

is made in the skin, by the action of high energy (per excited electron) short wavelength (~297 nanometre) ultraviolet B light, which breaks a bond between carbon atoms 9 and 10 in one of the rings of 7-dehydrocholesterol. This naturally occurs in the skin - though less so in old age - since it is one of the compounds in the chain of chemical reactions by which the body synthesizes cholesterol.

Our ancestors in Africa, 50,000 years and more ago, obtained almost all their vitamin D3 in this manner. However very few people today generate sufficient vitamin D3 to run their immune systems properly, for reasons including:

• This UV-B light is only available in substantial quantities from high-elevation, direct (no glass, sunscreen or clothing) sunlight on a cloud-free day. This is not available in winter, far from the equator, where billions of people live.

• There is almost no vitamin D3 in food, fortified or not. There is no such thing as a “vitamin D rich” food, which can supply a substantial fraction of the vitamin D3 we need for full immune system function.

• Most people in all countries today wear more clothing - and spend much more time in buildings and vehicles - than our African ancestors.

• People with dark or black skin and/or sun-avoidant lifestyles (for instance, many Muslim women) are at much greater risk of producing insufficient vitamin D3 themselves, especially when they live far from the equator. Those who live near the equator get much less direct sunshine in the monsoon months than they would need to produce adequate vitamin D, even if clothing, buildings, air pollution etc. were not further reducing their UV-B skin exposure.

• There are very good reasons for reducing UV-B skin exposure. The same range of UV-B wavelengths which create vitamin D3 also damages DNA and so increases the risk of skin cancer.

Fortunately, vitamin D3 tablets and capsules are inexpensive. Larger amounts can be taken every 7 to 10 days, so one 1.25 milligram (50,000 IU) capsule every week to ten days, provides what many adults need: 7000 to 5000 IUs a day, on average.

Vitamin D2 (ergocalciferol) is molecularly similar to vitamin D3, but is made by UV-B irradiating a chemical derived from yeast. It is not as effective at improving health as vitamin D3, which is the natural compound. (Jones et al. 2014 and Hicks 2022.) Although there are some more expensive non-animal sources of vitamin D3, the great majority of pharmaceutical vitamin D3 is made from 7-dehydrocholesterol derived from wool fat, in only a handful of factories worldwide, none of which are owned by major pharmaceutical companies.

Vitamin D3’s primary or sole role in the body is to be hydroxylated, mainly in the liver, to 25-hydroxyvitamin D (calcifediol, or “calcidiol”) which circulates in the bloodstream.

In people not suffering form obesity, only about 1/4 of ingested vitamin D3 goes into circulation as 25-hydroxyvitamin D. This is widely referred to as “vitamin D” but it is mistaken to do so. (Vieth 2004.) 25-hydroxyvitamin D is what is measured in “vitamin D” blood tests.

Government health agencies and many doctors regard a level (concentration) of 20 nanograms per millilitre (50 nanomoles per litre = 1 part in 50,000,000 by mass) as sufficient for good health. This is generally enough to supply the kidneys, so they can hydroxylate it to 1,25-dihydroxyvitamin D (calcitriol), which goes into the bloodstream at a very low level (less than 1 ng/mL). The kidneys carefully control this level of calcitriol, which functions as a long-distance, blood borne signaling molecule (a hormone) to control the behaviour of cells of several types in other parts of the body, which are involved in calcium-phosphate-bone metabolism.

All doctors understand these roles of the three compounds, of which only the third acts a hormone. While many doctors recognise that “vitamin D” (they tend to think of all three compounds as “vitamin D”) is important for the immune system, most do not understand that many types of immune cell require a good supply of 25-hydroxyvitamin D (calcifediol) in order to run their intracrine (inside an individual cell) and paracrine (to nearby cells) signaling systems.

These systems are unrelated to hormonal signaling. Since no peer-reviewed article (or any web page I could find) explains these in a tutorial fashion, I wrote such an explanation in detail vitamindstopscovid.info/02-intracrine/ and as part of my big page on vitamin D and the immune system: vitamindstopscovid.info/00-evi/#02-compounds .

Contrary to what some doctors and researchers assume, the immune system does not use hormonal signaling and is not affected by the very low level of circulating 1,25-dihydroxyvitamin D (calcitriol). Many types of immune cells - and so the entire immune system - can only work properly if they have a sufficient supply of the second compound: 25-hydroxyvitamin D.

It is clear that 50 ng/mL (125 nmol/L) circulating 25-hydroxyvitamin  D is needed for proper immune system function. A graph below, depicts rapidly rising risks of post-operative, bacterial, infections, the further below 50 ng/mL, the patient’s pre-operative 25-hydroxyvitamin D level was. This is 2.5 times the level governments and many doctors regard as adequate for good health.

Professor Wimalawansa’s recommendations are intended to ensure that every person attains at least 50 ng/mL circulating 25-hydroxyvitamin D, after several months, without danger of toxicity from much higher levels, such as over 150 ng/mL.

This is the first - and, to my knowledge, only - peer reviewed vitamin D3 supplemental quantity recommendation which aims to attain this goal, which all people need to be maximise their health.

His recommendations goes further, by specifically coping with the the needs of people who suffer from obesity. In order to raise their 25-hydroxyvitamin D levels to at least 50 ng/mL (125 nmol/L) obesity sufferers must ingest, or produce in their skin, a greater quantity of vitamin D3 per kilogram body weight than those not so suffering, because their bodies convert significantly less than about 1/4 of the vitamin D3 into circulating 25-hydroxyvitamin D. This is thought to be due to less hydroxylation in the liver and to excess adipose (fatty) tissue absorbing more of both vitamin D3 and 25-hydroxyvitamin D: vitamindstopscovid.info/00-evi/#obesity-deficit .

Prof. Wimalawansa’s recommended ratios of body weight, for daily vitamin D3 intake, on average, per day, for those suffering from obesity I or II (BMI 30 to 39) are:

• 100 to 130 IU / kg.

• 46 to 59 IU / pound.

• 1.1 to 1.5 mcg (micrograms) / kg.

This range of ratios is depicted in grey as the upper band in the graph above, and the middle band in the graph below.

For those suffering from obesity III (BMI 40 and above, previously known as morbid obesity), Professor Wimalawansa’s recommended ratios are:

• 140 to 180 IU / kg.

• 64 to 82 IU / pound.

• 1.6 to 2.0 mcg (micrograms) / kg.

These are depicted as the top band in the graph above. Obesity is a challenging, debilitating and potentially deadly medical condition requiring medical attention. These recommendations come from one of the world’s leading vitamin D researchers, but are not intended to replace advise given by an examining medical doctor.

These ranges of ratios are indicative of good vitamin D3 supplemental quantities.

Those who get a lot of direct, high-elevation, sunlight, on ideally white skin, can probably attain the desired 50 ng/mL 25-hydroxyvitamin D level with somewhat less than the amounts recommended here. However, such people would probably be better off protecting their skin from such strong UV-B exposure, and obtaining the vitamin D3 they need from supplements, as recommended above.

The upper ratios are not strict. If your BMI changes from 29 to 30, there is no need to suddenly increase your vitamin D3 intake to the 100 to 130 IU/kg/day level.

If your obesity status, according to BMI or clinical judgment, is borderline obesity, 90 to 110 IU/kg/day would be good guidance.

Derivations of the ratios of body weight

These ratios were based on Prof. Wimalawansa’s clinical experience and his interpretation of research including Ekwaru et al. 2014 journals.plos.org/plosone/article?id=10.1371/journal.pone.0111265 and Afshar et al. 2020 www.jocms.org/index.php/jcms/article/view/822. See the Update 2024-03-13 section below for a graph and further discussion of the Ekwaru et al. research.

Afshar et al. found that over 500 of their opthalmology patients, when advised to supplement 70 to 100 IU/day/kg body weight vitamin D3, over many years, attained between 40 and 90 ng/mL (100 and 225 nmol/L) circulating 25-hydroxyvitamin D. This is a very healthy outcome, with the only difficulty being that some people had less then the desired 50 ng/mL. Generally, these patients with the lowest levels would have been the ones who were suffering from obesity.

So this range of ratios was very good for non-obese patients, and a higher range of ratios for those suffering from obesity would enable these patients, as well, to attain at least the desired 50 ng/mL level of circulating 25-hydroxyvitamin D.

Short of a massive trial involving thousands of people, for a year or more, taking a wide range of quantities of vitamin D3 a day, there is no exact way of determining what such higher ranges of ratios would suit those suffering from obesity. However, Ekwaru et al. and research cited therein provides sufficient guidance for Prof. Wimalawansa to recommend the two higher ranges of ratios mentioned above. See also: vitamindstopscovid.info/00-evi/#06-ratios .

These steady vitamin D3 intakes will take two or so months to raise 25-hydroxyvitamin D levels over 50 ng/mL, from typical, unsupplemented, winter (or any all year round, for those with dark skin, far from the equator) levels of 25 ng/mL or less. To raise levels faster (this is my suggestion - and I am an electronic technician and computer programmer), it would suffice to take about 4 times the recommended amount for two weeks. This two-months worth of vitamin D in two weeks will accelerate the rise in levels by a month or more.

In clinical emergencies, such as sepsis, COVID-19, Kawasaki disease, MIS-C etc. the patient (who almost certainly has very low 25-hydroxyvitamin D) needs their level boosted in hours, not weeks or months. As described in Prof. Wimalawansa’s article and vitamindstopscovid.info/00-evi/#4.7, a single oral dose of 0.014 mg calcifediol, per kilogram body weight (obesity does not matter) will attain this potentially lifesaving outcome within 4 hours. For 70 kg, this is about 1 milligram - and it goes straight into circulation as the 25-hydroxyvitamin D the immune system needs.

Since calcifediol is usually not available except in Italy and Spain (see: vitamindstopscovid.info/04-calcifediol/), the next best approach is a single oral dose of about 10 mg (400,000 IU) vitamin D3, for a 70 kg person without obesity. This takes several days to attain at least 50 ng/mL, due to the need for hydroxylation in the liver. Prof. Wimalawansa’s article has recommendations along these lines.

Why 50 ng/mL (125 nmol/L) 25-hydroxyvitamin D or more?

Knowledgeable researchers and clinicians have been calling for 40 to 60 ng/mL circulating 25-hydroxyvitamin D to be recognised as the minimum required for good health, since 2008: www.grassrootshealth.net/project/our-scientists/.

You can spend a day or two reading the research articles cited and discussed at vitamindstopscovid.info/00-evi/ which indicate that 50 ng/mL or more is a good threshold of sufficiency. This includes research on COVID-19 and health problems such as pre-term birth, preeclamsia, schizophrenia, ADHD and autism and dementia.

The most direct evidence for proper immune system function requiring at least 50 ng/mL circulating 25-hydroxyvitamin D is from doctors at Massachusetts General Hospital: Quraishi et al. 2014: jamanetwork.com/journals/jamasurgery/articlepdf/1782085/soi130062.pdf:

Over five years, 700 morbidly obese patients underwent the same abdominal surgery to help them lose weight - Roux-en-Y gastric bypass. The two, almost identical, lines in the graph above depict the patients’ risk of post-operative surgical site infections and general hospital-acquired infections, plotted against their pre-operative 25-hydroxyvitamin D level on the horizontal axis.

The risks of these primarily bacterial infections was minimal (~2.5% for each type) as long as circulating 25-hydroxyvitamin D, before the operation - and so in the recovery period, since it is stable over a few weeks - was 50 ng/mL or more. With levels less than this, we see direct evidence of immune system failure: failure to control bacterial infections, which gets worse and worse the lower the patient’s 25-hydroxyvitamin D level.

25-hydroxyvitamin D is needed to supply immune cells internal signaling systems, which many type of immune cell rely upon for their ability to change their behaviour according to the conditions each such cell detects. Lower 25-hydroxyvitamin D levels cause these systems to fail, to a greater or lesser degree, causing the evident immune system dysfunction.

In general, this applies to all types of immune cells which use these signaling systems. The immune responses to cancer cells, fungi, parasites and viruses are mediated by similar types of immune cells as those which tackle bacterial infections. So it is reasonable to assume that all aspects of the immune system depend on a good supply of 25-hydroxyvitamin D in much the same way as its bacterial defenses do.

People suffering from obesity have generally lower than average 25-hydroxyvitamin D levels, so those patients with levels above about 25 ng/mL (75 nmol/L) would have attained these levels primarily or solely due to substantial vitamin D3 supplementation. There may be modest confounding effect due to these people being generally healthier, independent of their higher 25-hydroxyvitamin D levels, but most of the extraordinary degree of immune system weakness is surely caused directly by their low 25-hydroxyvitamin D levels.

Prof. Wimalawansa confirmed that there is no reason to believe that people suffering from obesity need higher 25-hydroxyvitamin D levels for full immune system function than do those not suffering from obesity. So, from this research alone (and it fits with a vast amount of other, less direct, evidence of this pattern of immune system dysfunction) we can reasonably conclude that 50 ng/mL or more circulating 25-hydroxyvitamin D is required to meet the needs of the immune system.

Perhaps some individuals would have full-strength immune responses with 40 ng/ml, and a very few with 30 ng/mL. This would be very difficult to test, so we have no way of knowing who these people are. 50 ng/mL or more should therefore be the threshold of sufficiency for all people.

On this basis, we can conclude that no matter what other nutrients and supplements the person consumes, and no matter what medical treatments they are taking, they cannot attain their best possible health unless their immune system is working properly - and this can only be assured with at least 50 ng/mL circulating 25-hydroxyvitamin D.

Potential problems with higher vitamin D3 intakes

High 25-hydroxyvitamin D levels can cause hypercalcemia. Calcium is drawn from the bone and the circulating (in the bloodstream) level of calcium, which should be very tightly controlled, rises to the point where calcification of arteries and heart valves can occur. This is potentially deadly, but, it typically takes 150 ng/mL or more 25-hydroxyvitamin D before such problems occur - and some people (at least with low calcium intake) can be healthy with twice this amount.

From the Endocrine Society’s Recommendations, Holick et al. 2011 academic.oup.com/jcem/article/96/7/1911/2833671:

Although it is not known what the safe upper value for 25(OH)D is for avoiding hypercalcemia, most studies in children and adults have suggested that the blood levels need to be above 150 ng/ml before there is any concern.

The body’s self limiting mechanisms make it very hard indeed to attain 150 ng/mL or more circulating 25-hydroxyvitamin D. There is almost (see Update 2024-03-13 below) no danger of raising levels so high when following Prof. Wimalawansa’s recommendations.

There are reports, not yet covered in the peer reviewed literature, of some people having heart palpitations when taking vitamin D3 supplements in quantities such as Prof. Wimalawansa recommends. See: https://vitamindstopscovid.info/00-evi/#adv . Any such ill effects indicate that the supplementation should be reduced or stopped. I will try to find out more about this apparently rare, and little researched, potential problem with vitamin D3 supplementation. I guess these people have an innate but usually hidden imbalance of some kind, which the vitamin D3 supplementation somehow alters to the point of being clearly noticeable.

Larger capacity vitamin D3 capsules

I am 68 kg (and 68 years old) and take a 50,000 IU vitamin D3 capsule once a week.

These: www.microingredients.com/products/vitamin-d3-plus-k2-mk-7 (240 caps for USD$30 plus shipping) are available with shipping to Australia, and I guess most other countries, via Amazon: amazon.com/dp/B0C35N273V. I have been taking this amount for about 4 years, and only recently had my 25-hydroxyvitamin D level tested for the first time. It was 96 ng/mL (240 nmol/L). There are doctors, especially in the UK, who would need an anxiolytic even thinking about such levels, but other, more knowledgeable doctors would be perfectly happy with this outcome. I have never felt better.

[Added 2024-03-13.] Via various online retailers, Amazon, eBay etc. it is easy to find capsules with larger amounts of vitamin D3 than the 0.025 mg (1000 IU) capsules which are the largest which can be sold in retail stores in Australia. 0.125 mg (5000 IU), 0.25 mg (10,000IU) and 1.25 mg (50,000 IU) are the most common capacities. Here are some such products:

• Bio-Tech Pharmacal are based in Arkansas, USA. They financially support the work of at least two of the vitamin D researchers I loosely collaborate with. My wife and I used these 1.25 mg (50,000 IU) capsules for several years: www.biotechpharmacal.com/collections/best-sellers/products/d3-50-50-000-iu-1. We switched to the MicroIngredients capsules mentioned above when the Bio-Tech shopping cart did not work for Australian customers and no Australian eBay sellers carried these capsules.

• Simon Goddek PhD, with whom I wrote an article on vitamin D for Brownstone.org, has a comprehensive once-a-day (for average weight adults) vitamin D3 (0.115 mg 5000 IU) and vitamin K2 (200 micrograms MK-7) capsule, which contains several other important nutrients: sunfluencer.com/product/vitamin-d-supplement/.

• Life Extension make a once-a-day capsule with 0.125 (5000 IU) vitamin D3, vitamin K1, two types of vitamin K2 and 1 mg (1000 micrograms) of iodine: www.lifeextension.com/vitamins-supplements/item02040/vitamins-d-and-k-with-sea-iodine. “Life Extension” is a pretty fancy name for a non-profit organization, but I know a 95 year old who has been taking this amount of vitamin D3 for two decades or so, on the advice of an enlightened doctor. In recent years these are the small capsules she has been taking. She has no life-threatening health concerns and shows no trace of cognitive decline.

Vitamin K2

Vitamin K2 (en.wikipedia.org/wiki/Vitamin_K2) supplementation, such as in the MK-7 form, is widely regarded as benefiting the immune system. There is also research which indicates that, with higher then normal 25-hydroxyvitamin D levels (the normal population levels are too low to be healthy), vitamin K2 MK-7 supplementation keeps calcium in the bone and reduces the risk of excessive blood calcium levels. There is a lot of research on vitamin K2. I will write about it when I have had time to properly survey the field. For now, please see: Maresz 2015, Gerry Schwalfenberg MD 2017 and Simon Goddek PhD, in the International Journal of Infectious Disease: Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate www.ijidonline.com/article/S1201-9712(20)30624-X/.

I take a 200 microgram vitamin K2 MK-7 capsule, with 1000 IU vitamin D3, each day. (bioglan.com.au/bioglan-vitamin-k2-d3-60-capsules) My calcium level was fine before I started taking the K2.

With these capsules and my daily multivitamin, I now supplement an average of 8342 IUs (0.208 mg) vitamin D3 a day. This is 123 IU / day per kg body weight. I am not suggesting everyone do this, but I am happy for my 25-hydroxyvitamin D levels to be far greater than the low levels which greatly raise the risk of dementia and other health problems.

5nn.info has some details of other nutrients which I think are worth supplementing.

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Addendum 2024-02-20: Here are two graphs which I refer to in my comment below, responding to Xavier’s comment concerning research which may indicate that there are worse cancer outcomes for some people with higher 25-hydroxyvitamin D levels. It will be a while before I can read that research and respond properly.

www.frontiersin.org/articles/10.3389/fnut.2021.740855

www.nature.com/articles/s41598-019-43462-6

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Update 2024-03-13

I added some links to higher capacity vitamin D3 capsules and to vitamin K2 research articles. I also added a note, above, that there is almost no risk that Prof. Wimalawansa’s recommendations would lead someone to attaining excessive 25-hydroxyvitamin D levels. Here is a more detailed discussion of this:

In very large populations, it is impossible to state with absolute certainty that there will be no ill-effects from any nutritional supplement.

I was recently included in an email discussion in which one of the world’s foremost vitamin D researchers mentioned that, in his long clinical and research career, he had encountered three vitamin D3 supplementing patients who had hypercalcemia, due to “markedly elevated” 25-hydroxyvitamin D levels, which were caused by a deficiency in the 24-hydroxylase enzyme. (The discussion was prompted by a BBC report of an 89 year old man’s death which a coroner judged to be due to “vitamin D toxicity, hypercalcemia, and cardiac and kidney failure.” His 25-hydroxyvitamin D level was 153 ng/mL 380 nmol/L. Many people die before their mid-80s due, in part, to lack of this vital nutrient.)

The activity of this 24-hydroxylase enzyme is generally proportional to the circulating 25-hydroxyvitamin D level. It adds and oxygen-hydrogen OH hydroxyl group to the 24th carbon of 25-hydroxyvitamin D (and also to vitamin D3 and calcitriol), which causes these molecules to be rapidly degraded by other processes. This has evidently evolved as a self-limiting mechanism to reduce 25-hydroxyvitamin D levels in the event of very high production of vitamin D3 in the skin and/or the person (more generally, the mammal) eating rare foods which contain significant amounts of vitamin D3 and/or 25-hydroxyvitamin D. (The livers of some fish, especially cod, and of some mammals evidently contain these.)

Without this 24-hydroxylase enzyme self-limiting system, the level of 25-hydroxyvitamin D in any one person would rise roughly linearly with the quantity of supplemental vitamin D3. However, in the following graph, adapted from Ekwaru et al. 2014 The Importance of Body Weight for the Dose Response Relationship of Oral Vitamin D Supplementation and Serum 25-Hydroxyvitamin D in Healthy Volunteers journals.plos.org/plosone/article?id=10.1371/journal.pone.0111265 the lines depicting how increasing intakes (horizontal) lead to 25-hydroxyvitamin D levels (vertical) roll off at higher levels, rather than continuing linearly to the upper right.

This data is from thousands of people, with varying vitamin D3 supplementation and different, self-reported, body types.

If we plotted the levels of the few people who are partly or entirely deficient in the 24-hydroxylase enzyme, we would have reasonably straight lines, to much higher levels, for any given body type and average daily vitamin D3 supplemental intake quantity.

As far as I know, this deficiency - which leads to a significant risk of hypercalcemia for people who supplement otherwise healthy amounts of vitamin D3 - is quite rare. This email discussion was the first mention of it I had encountered in four years of reading lots of vitamin D research.

As far as I know, short of experimenting with vitamin D3 supplementation accompanied by one or more blood tests, there is no way of determining who has this deficiency.

As you can read in research such as that cited and discussed at: vitamindstopscovid.info/00-evi/, there are dozens to hundreds of reasons why everyone should attain at least 50 ng/mL circulating 25-hydroxyvitamin D. The risk of a significant 24-hydroxylase deficiency is minimal - I guess 1/100,000 to 1/1000,000.

For instance, Patrick J McCullough MD and colleagues reported in 2019: Daily oral dosing of vitamin D3 using 5000 TO 50,000 international units a day in long-term hospitalized patients: Insights from a seven year experience, www.sciencedirect.com/science/article/abs/pii/S0960076018306228 their clinical experience in an Ohio psychiatric hospital, in which some patients were long-term residents:

During this time, we have admitted over 4700 patients, the vast majority of whom agreed to supplementation with either 5000 or 10,000 IUs/day. Due to disease concerns, a few agreed to larger amounts, ranging from 20,000 to 50,000 IUs/day. There have been no cases of vitamin D3 induced hypercalcemia or any adverse events attributable to vitamin D3 supplementation in any patient. Three patients with psoriasis showed marked clinical improvement in their skin using 20,000 to 50,000 IUs/day.

However, those who took the 20,000 to 50,000 IU/day quantities to suppress auto-immune conditions (as Dr McCullough takes for his own psoriasis) were doing so under medical supervision.

Just as the risk of not going to the doctor, of not visiting friends and family, of not going to work or school, of not traveling for pleasure, is so much greater than the small, but no-zero, risk that we will be injured or killed in a car accident, I think we should generally accept the very small risk of a bad outcome from vitamin D3 supplementation, rather than not do it, or do it tentatively at first, with one or more blood tests and possibly medical supervision.

Except for infants breast-fed by 25-hydroxyvitamin D mothers, and for those who get much more UV-B skin exposure than is healthy, everyone, from birth to death, needs to take vitamin D3 supplements in order to attain the 50 ng/mL 25-hydroxyvitamin D the immune system needs to function properly.

Blood tests of any type are not available in many remote and poor parts of the world. If a person has a family history of hypercalcemia, they certainly should proceed carefully and use “vitamin D” (really 25-hydroxyvitamin D) blood tests, ideally with medical guidance, to supplement only enough to attain the desired 25-hydroxyvitamin D level.

Some people are keen to test their 25-hydroxyvitamin D level, and there are home finger-tip prick mail-in test services which enable this to be done without great expense and without involving the medical profession. I could have done this in the past five or so years, but I didn’t bother, since I was confident my 25-hydroxyvitamin D and calcium levels were fine. I recently did get them checked as part of my doctor’s due diligence and found the calcium level to be within the narrow, proper, limits and my 25-hydroxyvitamin D level to be about what I expected

I don’t argue that anyone else needs my close to 100 ng/mL (250 nmol/L) 25-hydroxyvitamin D level, except those who are following the Coimbra Protocol or similar to suppress auto-immune inflammatory disorders, including cluster headaches and migraine. More on this at: vitamindstopscovid.info/06-adv/ .

In the absence of medical advice to test 25-hydroxyvitamin D level, Prof. Wimalawansa does not advocate blood tests for most people. His recommendations, above, are sufficient to enable the great majority of people to safely attain the desired 25-hydroxyvitamin D level.

To recommend everyone supplement vitamin D3 only with one or more blood tests would discourage most people from supplementing it at all.

Prof. Wimalawansa’s higher ratios for those suffering from obesity are based on long experience and on the Ekwaru et al. research. In the graph above, the light green dot for those suffering from obesity, which I added, is further to the right than the dots for normal and overweight people than can be explained solely by the obese people’s extra body weight. This is part of the now widely recognised evidence that people suffering from obesity need to supplement vitamin D3 in quantities determined by a higher ratio of body weight than suffices for people not suffering from obesity.