Cholecalciferol (Vitamin D3)

Cholecalciferol (Vitamin D3)

*Product image may differ from product received.


Product Details

What is Vitamin D3 (cholecalciferol)?

Vitamin D3, otherwise known as cholecalciferol, is a pro-hormone and essential nutrient produced in the skin. It is a seco-steroid hormone that regulates calcium homeostasis and balance within the body.

Vitamin D is best known for its role in the development and maintenance of healthy teeth, bones and cartilage. Vitamin D helps the body keep bones and teeth strong by improving the absorption of calcium and phosphorus from the small intestine. Vitamin D also affects parathyroid hormone (Wikipedia), which regulates bone turnover and release of calcium from bone.

There are two sources, vitamins D2 and D3. Vitamin D2, ergocalciferol, is considered a poor choice and is derived from sources such as fortified milk, herring, mackerel, tuna, salmon, sardines, eggs, fortified cereals and baked goods.

Vitamin D3, cholecalciferol, is the more active and preferable form of vitamin D. It is the most widely known of the vitamin D series. Vitamin D3 is preferred because it has a higher bioavailability and it has more roles in biological activity for its various metabolites or isomers that have biological benefit.

Vitamin D is known as the "sunshine vitamin" because it can be produced photochemically by the action of sunlight or ultraviolet light from the precursor sterol 7-dehydrocholesterol, which is present in the skin. Vitamin D formed in this manner is called "natural vitamin D" or vitamin D3. Sun exposure for just 15 minutes daily can provide 2,000 to 5,000 IU of vitamin D.

Vitamin D3 can also be obtained from animal products (such as eggs or fish) and fortified foods or can be consumed in the form of fish oil. As a fat-soluble vitamin, it is stored to a certain extent in the body.

Vitamin D deficiency can lead to serious effects. Children without adequate vitamin D are more susceptible to developing rickets, a disease characterized by deformation of bones and teeth. Adults with insufficient amounts of vitamin D have an increased risk of developing osteomalacia (similar to rickets), and are more likely to suffer from osteoporosis (Wikipedia), a bone-weakening disease.

The primary function of vitamin D is to promote and enhance calcium and magnesium absorption, the two essential minerals necessary for strong bones. Vitamin D3 is also required for the body to be able to utilize phosphorus, and for the absorption and metabolism of vitamin A.

By increasing GI absorption of phosphorus and calcium, cholecalciferol increases serum calcium concentrations, which in turn increases osteoclastic resorption and distal renal tubular reabsorption of calcium, whose optimal levels are required to ensure proper bone mineral density and serum (blood) calcium levels.

This is extremely beneficial among very young children where it can treat rickets in conjunction with vitamin A, and in the treatment of osteoporosis in the elderly, especially post menopausal women who often suffer from fractures due to loss of bone density.

Purity and Concentration of Vitamin D3 (cholecalciferol)

PureBulk's Vitamin D3 is a micro-encapsulated form, making it an excellent choice for pharmaceutical preparations. Due to the small size of these dry spherical particles, the vitamin can be distributed very homogeneously, even in formulations with a low active content. The product is also very suitable for the manufacture of vitamin D3 tablets, possessing a high active content by direct compression.

Stabilized with BHT, this dry powder is stable even in the presence of minerals, making it particularly suitable for use in in multivitamin/ mineral tablets and hard capsules.

This PureBulk Vitamin D3 (cholecalciferol) powder has a concentration of at least 100,000 IU/gram. (IU refers to International Units, a standard of measurement regarding the amount of the vitamin.) The spherical particles contain Vitamin D3 in medium chain triglyerides droplets of 1-2um, embedded in a matrix of gelatin and sucrose, coated with modified starch. The product contains t-butylhydroxytoluene (BHT) for stability.

Potential Side Effects of Vitamin D3 (cholecalciferol)

Like other fat-soluble vitamins, vitamin D can be TOXIC. Vitamin D supplements should be taken with caution!

Excess amounts can be stored in body tissue and may lead to hypercalcemia and excess bone loss. Individuals at particular risk include those with hyper-parathyroidism, kidney disease, sarcoidosis, tuberculosis, or histoplasmosis.

Symptoms of too much vitamin D include nausea, weakness, constipation, irregular heartbeat, weight loss, seizures and irritability.

Solubility and Suggested Preparation of Vitamin D3 (cholecalciferol)

Vitamin D3 is fat soluble and is not soluble in water. It is best to take this product at meal times with fatty foods.

How should I store it?

You will receive a resealable bag of this powder. Store in a cool, dry area protected from light. Reseal after each use.

References & Further Research

University of Maryland Medical Center: Vitamin D

Linus Pauling Institute: Vitamin D

The information at is NOT a substitute for medical advice. ALWAYS consult your doctor or pharmacist. Do not use any dietary supplement as a replacement for conventional care, or as a reason to postpone seeing a doctor about a medical problem. Tell all your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

The U.S. Food and Drug Administration (FDA) regulates herbal and other dietary supplements differently than conventional medicines. The standards for supplements are found in the Dietary Supplement Health and Education Act (DSHEA), a federal law that defines dietary supplements and sets product-labeling standards and health claim limits.

Tested by Accredited 3rd Party Labs

This PureBulk product is manufactured in a cGMP certified and registered facility. PureBulk's supplements are tested by accredited third party labs in the USA to ensure their identity, purity and potency. To receive a copy of these test results or any other PureBulk supplement please fill out the COA request form found here.

Supplement Facts & Directions

Supplement Facts

Serving Size: 50 milligrams
Servings Per Container: Varies
Amount Per Serving % Daily Value*
Vitamin D3 (as Cholecalciferol) 5085 IU1271%

* Percent Daily Values are based on a 2,000 calorie diet.
† Daily Value Not Established
‡ These supplement facts may vary from the product you recieve.    Please call for exact numbers.

Other Ingredients: Maltodextrin, Modified Starch, & Sucrose


Free of:  Soy, Dairy, Yeast, & Gluten

Directions:  As a dietary supplement, take 10mg to 50mg daily, or as directed by a physician. Accurate gram weight scale recommended.

Warning: If you are pregnant, nursing, taking any medications or have any medical condition consult your physician before use. Potentially toxic in higher quantities. Store in a cool, dark & dry place.

*NOTE: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.