• Maintains Bone Health
• Decreases risk of Colon & Colorectal Cancer
• Enhances Immunity
• Decreases pain Associated with Fibromyalgia
• Reduces risk of Breast Cancer
  

Vitamin D3 Supplements

It is not always practical to get your vitamin D from sunshine, and quite difficult to get adequate amounts from your diet so for many people, a vitamin D supplement is a practical way to ensure adequate levels of this important protector are always available in your bloodstream.
Since a large body of science shows vitamin D works closely with calcium and magnesium, it is best to take your vitamin D in combination with calcium and magnesium to maintain a proper balance. Recent literature also shows most calcium supplements have too little vitamin D to be effective. And some of them use synthetic vitamin D2. A much better form is natural vitamin D3 which stays in your system longer and with more effect.

There is a vast body of science showing the many health benefits of vitamin D. You may be surprised to learn the important role that vitamin D plays in your health.

Maintains Your Calcium Balance

Maintenance of blood calcium levels within a narrow range is vital for normal functioning of the nervous system, as well as for bone growth, and maintenance of bone density. Vitamin D is essential for the efficient utilization of calcium by the body.

Reduces Risk of Breast Cancer

There is growing evidence linking vitamin D and calcium in the diet to a reduced risk of breast cancer, but the benefits may be limited to younger women.

In a new study from Brigham and Women's Hospital and Harvard Medical School in Boston, a high intake of calcium and vitamin D through food sources and nutritional supplements was linked to modestly lower risk of breast cancer in premenopausal women.

The link appeared strongest for the most aggressive tumors, and it was not seen after menopause.

Researcher Jennifer Lin, PhD, says older women are more likely to be deficient in calcium and vitamin D, so they may need higher levels of the nutrients than were measured in the study.
"Calcium and vitamin D are important for overall health and, additionally, they may help prevent breast cancer," she tells WebMD.

Roughly 31,000 women enrolled in the larger Women's Health Study were included in the analysis by Lin and colleagues. The findings were published May 28 in the Archives of Internal Medicine.

All of the women were aged 45 or older, and two-thirds were postmenopausal. The women completed questionnaires at study entry and periodically after that were designed to determine their medical history and lifestyle, including the foods they ate and supplements they took.

Over an average of 10 years of follow-up, 276 premenopausal and 743 postmenopausal study participants developed breast cancer.

Premenopausal women with the highest intakes of calcium and vitamin D had modestly reduced risk of breast cancer compared with women who got the lowest amount of the nutrients through food and supplemental sources.

The findings are similar to those reported in 2002 by another group of Harvard researchers. In that study, calcium and vitamin D through dairy sources were associated with a decreased risk of breast cancer before, but not after, menopause.

Dietary calcium and vitamin D were found to lower breast cancer risk in a cancer prevention study reported by researchers from the American Cancer Society (ACS).

ACS nutritional epidemiologist Marji McCullough, ScD, RD, who reported the findings, tells WebMD that more study is needed to understand how vitamin D and calcium influence breast cancer risk."The evidence of a modest protective benefit [for dietary vitamin D and calcium] is fairly consistent, but we still don't know if premenopausal and postmenopausal women benefit equally," she says.

What About the Sun?

Current dietary recommendations call for people aged 50 and under to consume just 200 international units (IU) of vitamin D a day, with 400 IU recommended for those between the ages of 51 and 70, and 600 IU recommended after age 70.

Many experts now agree that these levels are too low. Longtime vitamin D researcher Cedric Garland, DrPH, says most people should get between 1,000 IU to 1,500 IU a day.

Aids Your Cell Differentiation

Cellular differentiation results in the specialization of cells for specific functions in your body. In general, differentiation of cells leads to a decrease in proliferation. While cellular proliferation is essential for growth and wound healing, uncontrolled proliferation of cells with certain mutations may lead to diseases like cancer. The active form of vitamin D, inhibits proliferation and stimulates the differentiation of cells.

Boosts Your Immunity

Active vitamin D is a potent immune system modulator. There is plenty of scientific evidence that vitamin D has several different effects on immune system function that may enhance your immunity and inhibit the development of autoimmunity.

Has a Role in Insulin Secretion

The active form of vitamin D plays a role in insulin secretion under conditions of increased insulin demand.  Limited data in humans suggests that insufficient vitamin D levels may have an adverse effect on insulin secretion and glucose tolerance in type 2 diabetes.

Vitamin D and Osteoporosis

Osteoporosis is most often associated with inadequate calcium intake. However, a deficiency of vitamin D also contributes to osteoporosis by reducing calcium absorption.  While rickets and osteomalacia are extreme examples of vitamin D deficiency, osteopororsis is an example of a long-term effect of vitamin D insufficiency.  Adequate storage levels of vitamin D help keep bones strong and may help prevent osteoporosis in older adults, in those who have difficulty walking and exercising, in post-menopausal women, and in individuals on chronic steroid therapy.  Vitamin D deficiency, which is often seen in post-menopausal women and older Americans, has been associated with greater incidence of hip fractures.  In a review of women with osteoporosis hospitalized for hip fractures, 50 percent were found to have signs of vitamin D deficiency.  Daily supplementation with 20 800 IU of vitamin D may reduce the risk of osteoporotic fractures in elderly populations with low blood levels of vitamin D.  The Decalyos II study examined the effect of combined calcium and vitamin D supplementation in a group of elderly women who were able to walk indoors with a cane or walker. The women were studied for two years, and results suggested that such supplementation could reduce the risk of hip fractures in this population.

Vitamin D and Cancer

Laboratory, animal, and some preliminary human studies suggest that vitamin D may be protective against some cancers. Several studies suggest that a higher dietary intake of calcium and vitamin D correlates with lower incidence of cancer.   In fact, for over 60 years researchers have observed that greater sun exposure reduces cancer deaths.  The inverse relationship between higher vitamin D levels in blood and lower cancer risk in humans is best documented for colon and colorectal cancers.  Vitamin D emerged as a protective factor in a study of over 3,000 adults who underwent a colonoscopy to look for polyps or lesions in the colon. There was a significantly lower risk of advanced cancerous lesions among those with the highest vitamin D intake.

Additional clinical trials need to be conducted to determine whether vitamin D deficiency increases cancer risk, or if an increased intake of vitamin D is protective against some cancers. Until such trials are conducted, it is premature to conclude you should take vitamin D supplements for cancer prevention.

Read more about the latest studies involving calcium and vitamin D reducing the risk of cancer
Vitamin D and Alzheimer's disease

Alzheimer's disease is associated with an increased risk of hip fractures because many Alzheimer's patients are homebound, frequently sunlight deprived, and older.  With aging, less vitamin D is converted to its active form. One study of women with Alzheimer's disease found that decreased bone mineral density was associated with a low intake of vitamin D and inadequate sunlight exposure.  More investigation on vitamin D and Alzheimer’s disease is necessary.

Other Diseases Vitamin D Deficiency May Affect

Autoimmune Diseases - Diabetes, Multiple Sclerosis and Rheumatoid Arthritis

Diabetes mellitus, multiple sclerosis, and rheumatoid arthritis, are each examples of autoimmune disease. Autoimmune diseases occur when the body launches an immune response to its own tissue, rather than a foreign pathogen. Treatment with vitamin D has beneficial effects in animal models of all of the above mentioned diseases. Studies have found that the prevalence of diabetes, multiple sclerosis, and rheumatoid arthritis increases as latitude increases, suggesting that lower exposure to sun light and associated decreases in vitamin D synthesis may play a role in the development of these diseases.

Vitamin D Toxicity

It is very rare to have a vitamin D overdose. Vitamin D toxicity induces abnormally high serum calcium levels (hypocalcaemia), which could result in bone loss, kidney stones, and calcification of organs like the heart and kidneys if untreated over a long period of time. When the Food and Nutrition Board of the Institute of Medicine established the tolerable upper intake level (UL) for vitamin D, published studies that adequately documented the lowest intake levels of vitamin D that induced hypocalcaemia were very limited. Because the consequences of hypocalcaemia are severe, the Food and Nutrition Board established a very conservative UL of 2,000 IU/day (50 mcg/day) for children and adults.

Research published since 1997 suggests that the UL for adults is overly conservative and that vitamin D toxicity is very unlikely in healthy people at intake levels lower than 10,000 IU/day.  Vitamin D toxicity has not been observed to result from sun exposure.

Certain medical conditions can increase the risk of hypocalcaemia in response to vitamin D, including primary hyperparathyroidism, acidosis, tuberculosis, and lymphoma.  People with these conditions may develop hypocalcaemia in response to any increase in vitamin D nutrition and should consult a qualified health care provider regarding any increase in vitamin D intake.

Tolerable Upper Intake Level (UL) for Vitamin D
Infants 0-12 months- 1000 IU
Children 1-18 years- 2000 IU
Adults 19 years and older- 2000 IU

Vitamin D is found in many dietary sources such as fish, eggs, fortified milk, and cod liver oil. The sun also contributes significantly to the daily production of vitamin D, and as little as 10 minutes of exposure is thought to be enough to prevent deficiencies. 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.

The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. Recently, research also suggests vitamin D may provide protection from osteoporosis, hypertension (high blood pressure), cancer, and several autoimmune diseases.

Rickets and osteomalacia are classic vitamin D deficiency diseases. In children, vitamin D deficiency causes rickets, which results in skeletal deformities. In adults, vitamin D deficiency can lead to osteomalacia, which results in muscular weakness in addition to weak bones. Populations who may be at a high risk for vitamin D deficiencies include the elderly, obese individuals, exclusively breastfed infants, and those who have limited sun exposure. Also, individuals who have fat malabsorption syndromes (e.g., cystic fibrosis) or inflammatory bowel disease (e.g., Crohn's disease) are at risk.

Vitamin D Drug Interactions

The following medications increase the metabolism of vitamin D and may decrease serum D levels:

Phonation (Dilating), fosphenytoin (Cerebyx), phenobarbital (Luminal), carbamazepine (Tegretol), and rifampin (Rimactane).

The following medications should not be taken at the same time as vitamin D because they can decrease the intestinal absorption of vitamin D:

Cholestyramine (Questran), colestipol (Colestid), orlistat (Xenical), mineral oil, and the fat substitute Olestra. The oral anti-fungal medication, ketoconazole, inhibits the 25(OH)D3-1-hydroxylase enzyme and has been found to reduce serum levels of 1,25(OH)D in healthy men . The induction of hypercalcemia by toxic levels of vitamin D may precipitate cardiac arrhythmia in patients on digitalis (Digoxin).