Vitamin D-3

Vitamin D is the name given to a vitally important group of micro-nutrients. When activated, vitamin D becomes a potent steroid hormone by switching our genes on or off and instructing our cells where they are needed within the body. Vitamin D's effects are varied and profound. It has a similar structure to steroids such as testosterone, cholesterol, and cortisol (though vitamin D3 itself is a secosteroid). The term "vitamin D" refers to several different forms of this vitamin. Two forms are important in humans: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D2 is synthesized by plants. Vitamin D3 is synthesized by humans in the skin when it is exposed to ultraviolet-B (UVB) rays from sunlight. Foods may be fortified with vitamin D2 or D3, although humans should not rely on synthetic food fortification as a good source of Vitamin D3.

Cholecalciferol (vitamin D3) has many health benefits when levels are kept optimal and away from deficiency. These benefits include;

Anti-Inflammatory- Chronic inflammation has become a major focus as a potential cause for various disease processes, such as heart disease and cancer. D-3, also called “The anti-inflammatory” hormone, has been studied as an effective treatment to reduce chronic inflammation. Vitamin D deficiency is often misdiagnosed as
fibromyalgia, chronic fatigue syndrome, and others. Deficiency has also been associated with multiple sclerosis, Graves’ disease, and age-related muscle wasting. Degenerative arthritis also progresses more rapidly when there is a deficiency of Vitamin D because of its anti-inflammatory properties.

Blood Sugar Control- Deficiency of Vitamin D and D3 can inhibit the proper secretion of insulin and lead to increased insulin resistance. Studies show that supplementing with D3, especially during winter months, can help prevent and reverse Type II diabetes. The effect of vitamin D3 on insulin secretion and peripheral insulin sensitivity in type 2 diabetic patients. (Borissova AM,
Tankova T, Kirilov G, Dakovska L, Kovacheva R. Source Department of Endocrinology, University Hospital, 6 Damjan Gruev str, 1303 Sofia, Bulgaria.)

Optimal Immune Function- Vitamin D helps the immune system fight infections. With a near-optimal blood level of vitamin D, you can expect fewer colds, flu, and other unwelcome opportunists (including Swineflu). Not only does Vitamin D enhance your immunity, but it inhibits the development of destructive
auto-immune diseases such as diabetes, rheumatoid arthritis, lupus, and multiple sclerosis.

Vitamin D is a major inhibitor of cancer, and part of this effect may be attributed to the increased vigilance of the immune system.

Blood Pressure- Optimal levels of Vitamin D3 tend to reduce blood pressure in hypertensive people. Supplementing with Vitamin D can help reduce the risk for hypertension.

Obesity- Deficiency of Vitamin D3 can lead to metabolic syndrome, which contributes to the rapid accumulation of fat mass.

Receptor Deficiency of Vitamin D can cause:

  • Depression (seasonal affective disorder)- Vitamin D modulates neurotransmitters in the brain.
  • Breast Cancer
  • Skin problems (i.e. Psoriasis)
  • Prostate Cancer
  • Interruption in immune response and production of lymphocytes
  • Ovarian Cancer
  • Islet cells of pancreas, which can lead to Diabetes
  • Muscle and bone aches, soreness, and pain
  • Aortic endothelium or Cardiovascular disease


How supplied:

Defy Medical offers Vitamin D3 from pharmaceutical sources which are tested for potency. Vitamin D3 comes in both capsule, sublingual, and injectable form.

Metabolic Maintenance

  • Vitamin D3 5,000iu, 90 capsules
  • Vitamin D3 10,000iu, 60 capsules

25% off any Metabolic Maintenance D3 ordered though Defy Medical.

Pharmacy Compounded:

  • Vitamin D3 25,000iu capsules
  • Vitamin D3 sublingual troches
  • Vitamin D3 50,000iu injectable, 5mL
  • Vitamin D3 100,000iu injectable, 5 or 10mL

How to Take D3:

Oral- 10,000iu per day is usually recommended for patients who are deficient. 25,000iu administered orally once per week is also commonly prescribed. For maintenance, we recommend 5,000iu per day orally. Injection- 0.25-0.5mL of 50,000iu vial, injected subcutaneously once weekly. Inject 0.05-0.25mL of 100,000iu vial subcutaneously, once weekly.

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Find out if you are Vitamin D3 Deficient

You can find out if you are deficient in D3 through a simple blood test which can be done anywhere in the US. The cost for the Vitamin D3 blood test is $48.

Click here to visit our blood testing page

Side effects:

Can too much vitamin D be harmful? Yes, it certainly can - though anything can be toxic in excess, even water. As one of the safest substances known to man, vitamin D toxicity is very rare. In fact, people are at far greater risk of vitamin D deficiency than they are of vitamin D toxicity (taken from The Vitamin D Council).

What is vitamin D toxicity?

Vitamin D toxicity is a condition where blood serum concentrations of vitamin D’s storage form, 25(OH)D or calcidiol, become too high, causing adverse systemic effects.

How it happens:

There is no risk of vitamin D toxicity due to sun exposure.

Since the body has a built-in mechanism for preventing toxicity from vitamin D produced in the skin, there is no risk of vitamin D toxicity due to ultraviolet-B (UVB) exposure - whether from the Sun or a tanning bed.

Supplemental vitamin D bypasses this built-in protection and, if excessive amounts are consumed over a period, 25(OH)D blood levels can reach a point where toxicity is possible.

Toxic doses

What exactly constitutes a toxic dose of vitamin D has yet to be determined, though it is possible this amount may vary with the individual.

Published cases of toxicity, for which serum levels and doses are known, all involve intake of > or = 40,000 IU (1000 mcg) per day. (1) Two different cases involved intake of over 2,000,000 IU per day - both men survived. (2, 3)

Serum levels: upper limit and toxicity threshold

The upper limit for a substance is the amount up to which is considered safe and without risk of adverse effects in most of the population.

Toxicity threshold for a substance is the amount beyond which over-saturation occurs and symptoms of toxicity manifest.

These values for 25(OH)D are as follows:

Toxicity threshold level - 200-250 ng/mL (500-750 nmol/L) (4, 5, 6, 7, 8)
Upper limit - 100 ng/mL (250 nmol/L)

The large range between 25(OH)D’s upper limit and its threshold value implies a degree of safety at serum levels up to 100 ng/mL (250 nmol/L), since concentrations twice this amount have yet to ever be associated with toxicity. (4)

In animal models, serum concentrations have reached as high as 400-700 ng/mL (1,000-1750 nmol/L) before toxic effects (severe hypercalcemia) were observed. (8, 9)

Symptoms: toxicity and overdose

Signs of vitamin D toxicity are high urine and blood calcium.

The first sign of vitamin D toxicity is hypercalcuria (excess calcium in the urine) followed by hypercalcemia (high blood calcium). The following symptoms may present:

  • nausea
  • vomiting
  • poor appetite
  • constipation (possibly alternating with diarrhea)
  • weakness
  • weight loss
  • tingling sensations in the mouth
  • confusion
  • heart rhythm abnormalities


The immediate symptoms of vitamin D overdose are:

  • abdominal cramps
  • nausea
  • vomiting


What to do if you think you have vitamin D toxicity:

Vitamin D is not toxic when used in the amounts nature intended.

It is difficult to become toxic using vitamin D3. If you are having an adverse reaction and believe you may be experiencing vitamin D3 toxicity; but you have not taken excessive amounts (like those described above), your symptoms could be due to reasons other than toxicity.

Test serum levels

First thing is to stop supplementation, then have your physician help you determine if you are toxic by testing your 25(OH)D levels. This is the same test used to determine vitamin D deficiency.

Rule out other possibilities

If results indicate levels lower than 200-250 ng/mL (500-750 nmol/L), you are most likely not toxic.

In this case, the reaction you experienced may be a result of:

An underlying magnesium deficiency. This is the most common reason for symptoms brought on by using vitamin D.

Vitamin D hypersensitivity due to pre-existing high blood calcium (hypercalcemia). Often mistaken for vitamin D toxicity, hypercalcemia is a rare condition usually caused by one of the following:
primary hyperparathyroidism (most common cause)
granulomatous TB
some cancers

If toxic, reduce serum levels

If the results show a serum 25(OH)D level of 200-250 ng/mL (500-750 nmol/L) or more, you could be toxic. The following measures should be taken until vitamin D levels return to normal:
avoidance of direct sunlight exposure
avoidance of foods and supplements containing vitamin D
restriction of calcium intake
drinking 8 glasses of water daily

Once 25(OH)D levels have normalized, sunlight exposure and/or vitamin D supplementation can be resumed, taking care not to overdo it.

In most cases, vitamin D toxicity can be corrected without lasting problems, provided the body has not remained in a hypercalcemic state for too long. Hypercalcemia has the potential to cause soft tissue calcification, resulting in deposits of calcium crystals in the heart, lungs, and/or kidneys. With prolonged hypercalcemia, permanent damage is possible if calcification is severe enough.


Vieth, R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. Am J Clin Nutr. 1999 May; 69 (5): 842-56.
Koutkia, P. Chen, T. C. Holick, M. F. Vitamin D intoxication associated with an over-the-counter supplement. N Engl J Med. 2001 Jul 5; 345 (1): 66-7.
Los Angeles Times Supplements guru sues over his own product. 2010/4/29;
Jones, G. Pharmacokinetics of vitamin D toxicity. Am J Clin Nutr. 2008 Aug; 88 (2): 582S-586S.
Heaney, R. P. Vitamin D: criteria for safety and efficacy. Nutr Rev. 2008 Oct; 66 (10 Suppl 2): S178-81.
Vieth, R. Vitamin D toxicity, policy, and science. J Bone Miner Res. 2007 Dec; 22 Suppl 2V64-8.
Vieth, R. Critique of the considerations for establishing the tolerable upper intake level for vitamin D: critical need for revision upwards. J Nutr. 2006 Apr; 136 (4): 1117-22.
NIH Office of Dietary Supplements Dietary Supplement Fact Sheet: Vitamin D. 2009/11/13;
Deluca, H. F. Prahl, J. M. Plum, L. A. 1,25-Dihydroxyvitamin D is not responsible for toxicity caused by vitamin D or 25-hydroxyvitamin D. Arch Biochem Biophys. 2010 Oct 18;
Baynes, John W, Dominiczak, Marek H. Medical Biochemistry 2nd edition. Elsevier Ltd 2005.
Robbins and Cotran. Pathologic Basis of Disease. Elsevier Ltd. 2005
Regalla, Sylvia MD. Dr. Jeffrey K.Harris Memorial Integrative Health Care Series. Rochester General Hospital. “Vitamin D; More than the sunshine vitamin”. October 17th,, 2009

These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.