Vitamin D
What is Vitamin D for?
Vitamin D is a vitamin. It can be found in small amounts in a few foods, including fatty fish such as herring, mackerel, sardines and tuna. To make vitamin D more available, it is added to dairy products, juices, and cereals that are then said to be “fortified with vitamin D.” But most vitamin D – 80% to 90% of what the body gets – is obtained through exposure to sunlight. Vitamin D can also be made in the laboratory as medicine.
Vitamin D is used for preventing and treating rickets, a disease that is caused by not having enough vitamin D (vitamin D deficiency). Vitamin D is also used for treating weak bones (osteoporosis), bone pain (osteomalacia), bone loss in people with a condition called hyperparathyroidism, and an inherited disease (osteogenesis imperfecta) in which the bones are especially brittle and easily broken. It is also used for preventing falls and fractures in people at risk for osteoporosis, and preventing low calcium and bone loss (renal osteodystrophy) in people with kidney failure.
Vitamin D is used for conditions of the heart and blood vessels, including high blood pressure and high cholesterol. It is also used for diabetes, obesity, muscle weakness, multiple sclerosis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), asthma, bronchitis, premenstrual syndrome (PMS), and tooth and gum disease.
Some people use vitamin D for skin conditions including vitiligo, scleroderma, psoriasis, actinic keratosis, and lupus vulgaris.
It is also used for boosting the immune system, preventing autoimmune diseases, and preventing cancer.
Because vitamin D is involved in regulating the levels of minerals such as phosphorous and calcium, it is used for conditions caused by low levels of phosphorous (familial hypophosphatemia and Fanconi syndrome) and low levels of calcium (hypoparathyroidism and pseudohypoparathyroidism).
Vitamin D in forms known as calcitriol or calcipotriene is applied directly to the skin for a particular type of psoriasis.
If you travel to Canada, you may have noticed that Canada recognizes the importance of vitamin D in the prevention of osteoporosis. It allows this health claim for foods that contain calcium: "A healthy diet with adequate calcium and vitamin D, and regular physical activity, help to achieve strong bones and may reduce the risk of osteoporosis.” But the US version of this osteoporosis health claim does not yet include vitamin D.
What is Vitamin D Possibly 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.
• 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. But taking vitamin D supplements doesn’t seem to provide the same benefit.
• 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."
