Benefits of Vitamin D3 (Cholecalciferol)

Please DO NOT forget to take co-factors when taking Vitamin D3!  A Vitamin D3 deficiency REDUCES the benefits of Progesterone. 
Regardless of whether you use progesterone or not, vitamin D3 and its co-factors are vital for our health. These nutrients are particularly helpful in building our immune system and guarding against COVID-19. Stay safe everyone and do the right thing.

Vitamin D3 - as well as being a vitamin, it is actually a hormone as well, and possibly as old as progesterone.  It has excellent anti-oxidative and autoimmune anti-inflammatory mechanisms. It positively affects the nervous system by stimulating neurotrophic factors, quenching oxidative hyperactivity and regulating autoimmune responses.

It is made by the action of UVB sunlight as it strikes the cholesterol covering our bare skin. Unfortunately with our habit of washing with soap, cholesterol is washed off, leaving very little with which to make Vitamin D3. This is why we all need to supplement.  One misguided piece of information is covering up and using excessive sunscreen whilst in the sun. This should only be applied after having been in the sun for about 15 - 30 minutes, dependent on skin type. 

 Dr John J Cannell MD, a psychists believed that there were likely bad consequences in getting so little sun exposure (cough, vitamin D deficiency) and wanted to do something about it. So, he founded the Vitamin D Council in 2003 to educate the public on the importance of sun exposure and vitamin D.  The Vitamin D Society and GrassrootsHealth websites are also excellent websites for information on vitamin D3.  

 Get yourself tested, ZRT Labs and Birmingham Hospital are excellent for online testing labs.


Vitamin D3 and Co-factors - why are they important?


Vitamin D3 helps the body absorb calcium from the diet. Vitamin K2 directs the body to deposit the calcium in the places where it is needed, such as bones and teeth and NOT in organs, arteries, muscles and soft tissue where it can cause health issues. It is Magnesium's job to keep it where it belongs. Vitamin D3, Magnesium and Vitamin K2 are no brainers!


During the last decade, ground-breaking laboratory studies have shown that the active hormone form of Vitamin D3 interacts with receptors in more than 30 tissues and organs of the body and influences the action of some 1000 or more genes.  Vitamin D3 controls not only calcium homeostasis but another five physiological systems: the immune system, pancreas beta cells, heart and blood vessels, muscle development and strength, and brain development. In addition, Vitamin D3 has direct effects on cell activity. It facilitates cell differentiation and apoptosis, that is, it regulates cell death. Together with calcium, it has a profound effect on cellular adhesion and initiation of cancer.


Between 30-50% of people have a deficiency, particularly those living in climates with little sun, living above 34 degrees north or south of the equator, work indoors, spend little time in the sun and have dark skin.  The darker the skin the more sun exposure is required to obtain sufficient penetration.  Recent studies show that 1 out of 381 Indian women had a sufficient level.  Now that is scary!   People living in the Middle East have a major problem in the form of rickets. The following gives an indication on levels of Vitamin D3 found in the blood.  The test should be done for 25-hydroxyVitamin D3, also called calcidiol.

  • Sufficient: 70-100ng/ml or 175-250 nmol/L
  • Hypovitaminosis: <30ng/ml or 75 nmol/L
  • Deficiency: <25ng/ml or 62 nmol/L

Children under 5 years of age should take 2 000iu’s per day!

 Do not get confused between Vitamin D2 (Ergocalciferol) versus Vitamin D3 (Cholecalciferol

Not many people know there are two types of Vitamin D3, and they are NOT interchangeable!  In fact, taking the wrong one could do you more harm than good.  Drisdol is a synthetic form of Vitamin D2—made by irradiating fungus and plant matter—and is the form of Vitamin D3 typically prescribed by doctors.  This is not the type produced by your body in response to the sun which is Vitamin D3.  Make sure that the Vitamin D prescribed or bought at a pharmacy is Vitamin D3!

Vitamin D2 is found in a lot of our foods  i.e. mushrooms.  It is Vitamin D3 that we need, the same vitamin that we get from the sun.  Certain foods contain it  i.e.  salmon but we need to eat huge quantities to get the amount that is needed!

Some Vitamin D3 supplements come with added vitamin A and/or calcium, do be careful.  Vitamin A if taken in large quantities can become toxic and will block the uptake of Vitamin D3.  Too much free calcium in the blood can result in calcified arteries, heart disease and depression. Please see references below.

VITAMIN A - Do not take cod liver oil (CLO) or ANY fish liver oil.  The excessive vitamin A it contains prevents Vitamin D3 from being absorbed and can become toxic - see here.  Take beta-carotene if deficient in vitamin A.  It is also believed that excessive vitamin A is responsible for Hair Loss.


To clear any confusion, 'fish oil' comes from the muscle of the fish and contains Omega 3.  'Fish liver' comes from the liver, it contains large amounts of vitamin A and very small amounts of Vitamin D3.  There is a huge difference between the two. We should all be taking Omega 3 fish oil.

The most important nutrient needed for strong bones is Vitamin D3, see here.

The recommended daily dose of Vitamin D3 is 5 000iu's for adults and 2 000iu's for children under the age of 5 years. Your Vitamin D3 level should be between 70ng/ml and 100ng/ml and it needs to be maintained there.  I took 15 000iu's of Vitamin D3 for about 9 months and then went to have my level tested, it came back at 139ng/ml.  I want to maintain this level and take nothing less than 5 000iu's Vitamin D3 a day.  When stressed, I increase the dose for a few days.  
Listed are a few modern day diseases and syndromes where evidence is pointing to a Vitamin D3 deficiency:

  • autism
  • auto-immune diseases
  • diabetes
  • colds and flu
  • septicemia
  • eczema
  • rosacea
  • psoriasis
  • lupus
  • muscle pain
  • osteoporosis
  • oseomalacia
  • asthma
  • depression
  • dipolar
  • Hypertension
  • obesity - these people need 2-3 times more Vitamin D3
  • multiple sclerosis (MS)
  • IBS
  • insomnia
  • seizures
  • cystic fibrosis
  • fibroids
  • endometriosis
  • PCOS
  • alzheimer's
  • arthritis
  • fibromyalgia
  • peripheral neuropathy
  • Crohn's disease
  • Dementia
  • Infertility
  • Schizophrenia
  • cancer - please see here and this video by Dr Carole Baggerly


Toxicity has always been a concern, but it appears to be another misguided piece of information, see here and here.

Please take the time to view this amazing video by Dr Michael F Holick, it is long but well worth the view and explains so much.
Vitamin D3 comes in three forms:

  • Cholecalciferol or D3 which is formed in the skin, this also comes as a supplement to take.
  • Calcidiol (25-hydroxyVitamin D3) is a pre hormone made from cholecalciferol by the liver. When testing for Vitamin D3 this, and only this, is what should be tested for.
  • Calcitriol (1,25-dihydroxyVitamin D3) is made from calcidiol principally by the kidneys, and is a most potent steroid hormone.

Finally a lack of Vitamin D3 reduces the benefits of progesterone, see here and here.

I highly recommend that you have your Vitamin D3 level tested so that you can address the situation should attention be needed.

Vitamin D3 and Co-Factors

Vitamin D3 does need Co-Factors to work optimally, Magnesium (Mg), Vitamin K2 (MK:7), Boron and Zinc. Magnesium is thought to be the most important.  If you are low in magnesium and take Vitamin D3, or if you make it via the sun, you may feel many adverse symptoms, cramping being one of them.  The following papers will give you some idea of the role magnesium plays, see here, here and here.

Between 250 - 800mg of magnesium should be taken daily, depending on how deficient one is.  Individuals need to experiment to see what suits them best. The ideal combination is oral and transdermal in the form of Epsom Salt baths/foot baths and Magnesium oil.  A note of caution if taking a high dose of magnesium, it has a laxative effect, start on a lower dose and work up. From my own personal experience I have found that 200mg Magnesium Citrate in the morning and 200mg Magnesium Glycinate at night works extremely well for me, then I use the transdermal applications.  You need to experiment with the different types of magnesium, find one that suits you.  When taking and using magnesium it is important that you are well hydrated

If supplementing then 100mcg of K2 (MK:7) is needed per day.  Don't forget we get this from our food as well.

TIP: When taking Vitamin D3 in the morning take it with something fatty, like MCT oil or cheese. It is believed that it helps with the absorption of D3

Some information on the roles of Vitamin D3, Magnesium and Vitamin K2(MK:7) - no soy

Vitamin D3 helps the body absorb calcium from the diet. Vitamin K2 directs the body to deposit the calcium in the places where it is needed, such as bones and teeth and NOT in organs, arteries, muscles and soft tissue where it can cause health issues. It is Magnesium's job to keep it where it belongs. Vitamin D3, Magnesium and Vitamin K2 are no brainers!

Note on calcium: We do not need to supplement with calcium unless your are chronically deficient. Please view these excellent videos, they are well worth the view.  Death by Calcium and Too Much Calcium.

Please watch this video - The Vitamin K2 and Calcium Paradox


I am adding the Adrenal Fatigue Cocktail here as it really does help with stress and anxiety and helps with adrenals.  It really does work.



Take the following 1-2 times/day an hour before or after food. Do NOT use this first thing in the morning. This cocktail will nourish the adrenals when needed.

One application:
* 4oz/125ml freshly squeezed Orange or Grapefruit Juice – the vitamin C makes sure that the minerals noted below get to the liver to nourish the adrenals
* 1/4 tsp of Cream of Tartar - this is an
excellent source of Potassium
* 1/4 tsp of fresh ground Himalayan Sea Salt - this is an excellent source of Sodium and other minerals
Mix the above at the start of the day with enough liquid for two (2) applications i.e. 8oz/125ml of orange juice. Drink it mid-morning, as well as mid-afternoon. In addition, any time that you are feeling particularly anxious it would be advisable to prepare another mixture and take it.

Please note: For those who have blood sugar problems, use lemon juice mixed with a little water, you are looking for vitamin C.


Recommended Vitamin D3  Supplement

South Africa

Metagenics D3 Liquid

USA and UK

Bio-Tech - proceeds go to research
Doctor's Best
Now Foods



Can you overdose on Vitamin D3 - It's harder than you think

Researchers report an extremely high prevalence of vitamin D3 deficiency in Indian women

A Brief History of Early Sun Therapy

Death by Calcium

Higher vitamin D status during early pregnancy may reduce depressive symptoms in Brazilian women

Low levels of serum vitamin D3 are associated with autoimmune thyroid disease in pre-menopausal women

New study finds derivative of activated vitamin D helps manage hair loss

Vitamin D Deficiency- An Ignored Epidemic

The role of vitamin D3 in the mental health of older adults

Peripheral Neuropathy

Meta-analysis finds relationship between low vitamin D levels and kidney cancer

Prenatal vitamin D supplementation helps strengthen bones for babies born in winter

"Multiple Sclerosis is almost 100% preventable," says Dr. Cedric Garland in an editorial

Vitamin D3 and Autism

The truth about Vitamin A Toxicity - Hair Loss


Low Vitamin D3 relates to irregular menstrual cycle

The Importance of Magnesium

Magnesium - the overlooked mineral

Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis

Smoking Reduces Vitamin D3

Vitamin D3 and Tuberculosis

New study suggests targeting Vitamin D3 receptors could help in breast cancer in the further

Whilst this refers to Canada, it applies WORLD WIDE - An estimate of the economic burden and premature deaths due to Vitamin D3 deficiency in Canada

Association of hypogonadism with Vitamin D3 status: the European Male Ageing Study

Am I deficient in Vitamin D3?

Sunshine Could Benefit Health and Prolong Life, Study Suggests

Month of Birth Impacts Immune System Development

Two New Vitamin D3 Blood Tests Are Often Highly Inaccurate, Researchers Say

Low serum 25-hydroxyVitamin D3 is associated with increased risk of the development of the metabolic syndrome at five years: results from a national, population-based prospective study (The Australian Diabetes, Obesity and Lifestyle Study: AusDiab).

Vitamin D3 - one of the Oldest Hormones

Vitamin D3 deficiency in UK a 'major problem'

Vitamin D3, sunlight and cancer connection.

Effects of Vitamin D Therapy on Quality of Life in Patients with Fibromyalgia

Vitamin D3 deficiency in women with fibromyalgia in Saudi Arabia


The world epidemic of sleep disorders is linked to Vitamin D3 deficiency.

Vitamin D3 Isolated in 1937

Vitamin D3 deficiency associated with severe adult asthma

Depressed adolescents in a case-series were low in Vitamin D3 and depression was ameliorated by Vitamin D3 supplementation

Calcium Supplementation - Osteporosis and Psychological Problems

Multiple Sclerosis and Vitamin D3: A Patient Friendly Summary

Cod Liver Oil, Vitamin A Toxicity, Frequent Respiratory Infections, and the Vitamin D3 Deficiency Epidemic

Maternal early-pregnancy Vitamin D3 status is associated with maternal depressive symptoms in the Amsterdam Born Children and Their Development cohort.