Health Benefits of Vitamin D and Debating If You Should Take A Vitamin D Supplement Are In the Spotlight
Benefits of Vitamin D for Children
In October 2008, The American Academy of Pediatrics (AAP) began recommending twice the previously recommended vitamin D intake for infants, children, and young adults. Benefits of vitamin D in children include prevention and treatment of rickets. Adequate intake all during childhood may also reduce later incidence of osteoporosis. New guidelines call for vitamin D intake of no less than 400 international units (IU) daily for all infants and children.1
AAP also advises that levels be monitored during pregnancy due to evidence that the vitamin plays a role in fetal development.1
Benefits of Vitamin D for the Elderly
The need for vitamin D supplementation increases as we age because the body makes less of it in the skin and less is converted to its active form in aging kidneys. Elderly people also tend to get less sun exposure, increasing their need for supplementation.
Deficiency causes muscle weakness. Supplementation has been shown to prevent falls in elderly patients who are vitamin D deficient. The role of calcium in fall prevention is not known, but adequate calcium is important for other health reasons such as bone density and appropriate vitamin D levels are critical to calcium’s absorption.
Improving muscle strength in the elderly may require higher vitamin D levels than previously thought, at least 800 IU per day.2
Benefits of Vitamin D in All Age Groups
Because of its role in calcium absorption and bone health, The National Osteoporosis Foundation recommends that people less than 50 years of age have an intake of 400 to 800 IU of vitamin D3. People over 50 should get between 800 and 1,000 IU daily.3
There is recent evidence that people with higher vitamin D levels may get less cancer, but the American Cancer Society (ACS) says that further studies are needed to clarify the role of the vitamin in preventing cancer. There has also been interest in vitamin D supplementation as a treatment for some types of cancer, but ACS is also calling for further studies to confirm this also.4
The American Heart Association (AHA) found that risk of heart disease was 62% higher in patients with low vitamin D levels, and that the highest risk is in patients with high blood pressure. This finding was consistent over a five-year follow-up of the patients they studied. Further studies are recommended to prove whether raising vitamin D intake can prevent heart disease. Meanwhile, AHA recommends that people stay healthy by eating a variety of healthy food sources of vitamin D such as fortified milk, salmon, mackerel, sardines, cod liver oil and fortified cereals. They believe that better heart-related outcomes depend more on a healthy diet than on supplementation.5
American Diabetes Association reports that adequate Vitamin D intake appears to reduce the risk of developing type 2 diabetes. They are calling for further studies in this regard before recommending it for prevention.6
Please continue on to page two of this article to find out more information about vitamin D intake.
More Information About Vitamin D Intake
Dietary sources of vitamin D appear to be inadequate and it is difficult to determine a safe level of sunlight exposure that will allow the body to make sufficient vitamin D but avoid potential skin cancers.7
People who have poor dietary intake and decreased sun exposure are not the only groups who are vitamin D deficient. People with dark skin have an increased amount of a pigment called melanin. Melanin reduces the skin’s ability to make sufficient vitamin D from sunlight. Those with vitamin D metabolism disorders are at greater risk. Obesity does not interfere with natural production of vitamin D in the body but the vitamin tends to be held in fat cells rather than being released into the circulation. Malabsorption problems occur in other medical conditions such as when there is a deficiency of pancreatic enzymes, in Chron’s disease, in cystic fibrosis, in certain types of liver disease, and when parts of the gastrointestinal tract have been surgically removed.7
Vitamin D supplementation has been shown to significantly reduce overall incidence of death from any cause.7
Vitamin D occurs in two different forms, D2 (ergocalciferol) and D3 (cholecalciferol). The D3 form is best for raising and maintaining healthy levels.7
The safe upper limit for vitamin D supplementation is not well established, but excessive intake can result in kidney stones, nausea, vomiting, diarrhea, and constipation. Exposure to the sun and vitamin D intake from the diet are not expected to cause toxicity. The upper tolerable intake level is generally recognized to be 2,000 IU per day.7
There are a number of potential drug interactions with this vitamin. Those who take prescription medications should disclose any vitamin D supplementation to their doctor and pharmacist.
Only a blood test can verify the presence of a vitamin D deficiency.8
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Reference Materials
(1) New Guidelines Double the Recommended Amount of Vitamin D
(2) Print article: Geriatrics; Pharmacist’s Letter; June 2008; Vol: 24
(4) Vitamin D
(5) Lack of Vitamin D May Increase Heart Disease Risk
(6) Vitamin D May Curb Type 2 Risk
(7) Dietary Supplement Fact Sheet: Vitamin D
(8) Key Gaps Remain in Understanding Health Effects of Vitamin D