Clipped Sept 2011 from Medline Plus

Effective for...

• Treating conditions that cause weak and painful bones (osteomalacia).
• Low levels of phosphate in the blood (familial hypophosphatemia).
• Low levels of phosphate in the blood due to a disease called Fanconi syndrome.
• Psoriasis (with a specialized prescription-only form of vitamin D).
• Low blood calcium levels because of a low parathyroid thyroid hormone levels.
• Helping prevent low calcium and bone loss (renal osteodystrophy) in people with kidney failure.
• Rickets.
• Vitamin D deficiency.

Likely effective for...

• Treating osteoporosis (weak bones). Taking a specific form of vitamin D called cholecalciferol (vitamin D3) along with calcium seems to help prevent bone loss and bone breaks.
• Preventing falls in older people. Researchers noticed that people who don’t have enough vitamin D tend to fall more often than other people.
  They found that taking a vitamin D supplement reduces the risk of falling by up to 22%.
  Higher doses of vitamin D are more effective than lower doses.
  One study found that taking 800 IU of vitamin D reduced the risk of falling, but lower doses didn’t.
• Also, vitamin D, in combination with calcium, but not calcium alone, may prevent falls by decreasing body sway and blood pressure.
  This combination prevents more falls in women than men.
• Reducing bone loss in people taking drugs called corticosteroids.

Possibly effective for...

• Reducing the risk of multiple sclerosis (MS). Studies show taking vitamin D seems to reduce women’s risk of getting MS by up to 40%.
  Taking at least 400 IU per day, the amount typically found in a multivitamin supplement, seems to work the best.
• Preventing cancer. Some research shows that people who take a high-dose vitamin D supplement plus calcium might have a lower chance of developing cancer of any type.
• Weight loss. Women taking calcium plus vitamin D are more likely to lose weight and maintain their weight.
  But this benefit is mainly in women who didn’t get enough calcium before they started taking supplements.
• Flu. Some research in school aged children show that taking a vitamin D supplement during winter might reduce the chance of getting seasonal flu.
• Reducing the risk of rheumatoid arthritis in older women.
• Reducing bone loss in women with a condition called hyperparathyroidism.
• Preventing tooth loss in the elderly.

Possibly ineffective for...

• Breast cancer. Many studies have looked at whether vitamin D can help prevent breast cancer, but their results have not always agreed.
  The best evidence to date comes from a large study called the Women’s Health Initiative, which found that taking 400 IU of vitamin D and 1000 mg of calcium per day does not seem to lower the chance of getting breast cancer.
  The possibility remains that high doses of vitamin D might lower breast cancer risk in younger women. But the doses needed would be so high that they might not be safe.
• High blood pressure.
• Improving muscle strength in older adults.
• Preventing bone loss in people with kidney transplants.

Insufficient evidence to rate effectiveness for...

• Heart disease. Research suggests that people with low levels of vitamin D in their blood are much more likely to develop heart disease, including heart failure, than people with higher vitamin D levels. However, taking vitamin D does not seem to extend the life of people with heart failure.
• High cholesterol. People with lower vitamin D levels seem to be much more likely to have high cholesterol than people with higher vitamin D levels.
  Limited research shows that taking calcium plus vitamin D daily, in combination with a low-calorie diet, significantly raises “good (HDL) cholesterol” and lowers “bad (LDL) cholesterol” in overweight women. But taking calcium plus vitamin D alone, does not reduce LDL cholesterol levels.
• Gum disease. Higher blood levels of vitamin D seem to be linked with a reduced risk of gum disease in people 50 years of age or older.
  But, this doesn’t seem to be true for adults younger than 50.
• Diabetes. People with lower vitamin D levels are significantly more likely to have type 2 diabetes compared to people with higher vitamin D levels.
  But, there is no reliable evidence that taking vitamin D supplements can treat or prevent type 2 diabetes.
• Premenstrual syndrome (PMS). There is some evidence that getting more vitamin D from the diet might help to prevent PMS or reduce symptoms.
  Taking vitamin D supplements might help reduce symptoms but doesn't seem to help prevent PMS.
• A blood cell disease called myelodysplastic syndrome.
• A muscle disease called proximal myopathy.
• Colorectal cancer.
• Warts.
• Bronchitis.
• Asthma.
• Breathing disorders.
• Metabolic syndrome.
• Muscle pain caused by medications called "statins."
• Vaginal atrophy.
• Other conditions.

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Note: The above is generally based on < 2,000 IU of vitamin D.

Much higher doses are needed for TREATMENT

See also Vitamin D Life

• All items Strength of Evidence for D 18 items as of Nov 2011