Vitamin D Facts

The role of vitamin D in calcium absorption and bone health is well known. The overwhelming amount of research over the past twenty years has suggested that vitamin D has many other benefits. Research has also indicated that Vitamin D deficiency is not rare; on the contrary it has a very high prevalence and is even recognized as a major health problem for older adults. Presented below is a summary of the published scientific research findings on Vitamin D. For additional information and references, please refer to the Vitamin D article posted on our “Science” section.

• Sunlight is the primary source of vitamin D.
• A very small number of foods naturally contain vitamin D;
  • oily fish such as salmon, mackerel, and sardines
  • irradiated mushrooms
  • cod liver oil

- Recent studies in humans have provided evidence that vitamin D3 (cholecalciferol from animal sources) is more efficient than vitamin D2 from plant sources.

Deficiencies
- 41% of healthy adults, 49 to 83 years of age are found to be vitamin D deficient.

- Students and young adults are also vitamin D deficient, especially those who work inside or who always wear sun protection.

- Individuals who have darkly pigmented skin, those who are obese and the elderly have an increased risk of vitamin D deficiency.

Elderly care
- In adults, vitamin D maintains bone mineral density and prevents osteoporosis.

- The body’s largest source of calcium is found in bones, which are then used to maintain serum levels. When vitamin D is low, more bone is needed as a source of calcium to support balanced levels.

- Vitamin D has a direct effect on muscle strength and is thought to maintain function of type II muscle fibers which could reduce risk of falling and fractures in the elderly.

- Falls are the single most common cause of injury mortality in the elderly and account for 40% of all nursing home admissions.

Pregnant/Nursing mothers and Infants
- Vitamin D regulates calcium/phosphorus absorption and metabolism for bone health.

- This role becomes more important during pregnancy and lactation as bones are developing rapidly during this period.

- Insufficient vitamin D intake during pregnancy can lead to low birth weight and/or result in the symptoms of rickets in infancy;

• biochemical disturbances
• reduced bone mineralization
• slower growth
• bone deformities
• increased risk of fracture

Protection from cancer
- Studies have shown that vitamin D helps prevent breast, colorectal, ovarian and prostate cancers.

Diabetes
- Clinical trials have suggested that vitamin D and calcium supplementation could have a role in the prevention of type 2 diabetes in populations at high risk.

- A study which began in 1966 administered 2000 IU of vitamin D to children and revealed there was an 80% reduction in the development of type 1 diabetes though-out the following 30 years in those children.

Protection from inflammation and cold/flu
- Vitamin D plays an important role in the regulation of immune system function and suppresses T-helper cell over-activity, and works to prevent autoimmune diseases such as type-1 diabetes, rheumatoid arthritis, scleroderma, and graft rejection.

- A recent randomized controlled trial gave evidence that vitamin D provides a dramatic preventative effect against influenza and colds.

- Vitamin D stimulates the expression of potent anti-microbial peptides and protects the lung from infection.

- A low dose (800 IU/day) reduced reported incidence of cold or flu, and abolished the seasonality of cold and flu reports.

- A higher dose (2000 IU/day), given during the last year of the trial, eliminated all reports of colds or flu.

Cardiovascular Disease
- Researchers now believe that vitamin D deficiency could contribute to congestive heart failure.

- Calcium and vitamin D supplementation results in a 9.3% decrease in systolic blood pressure, a 5.4% decrease in heart rate and substantially reduces C-reactive protein levels in critically ill patients.

Disorders of the brain and cognition
- Vitamin D receptors are present in the brain.

- A review of older adults found a positive correlation between score on the mini-mental state examination and serum vitamin D levels.

Multiple sclerosis
- Intake of Vitamin D is associated with a lower incidence of MS and vitamin D supplementation is often recommended in the early stages of MS to lower the risk of osteoporosis.

Mood and well-being
- Vitamin D levels are related to positive mood and well-being
People who suffer from unipolar and bipolar depression have significantly lower levels of vitamin D.

- In a randomized study, eight subjects with seasonal affective disorder given vitamin D supplementation showed improvements in depression measures.