Vitamin D Deficiencies – Osteoporosis and Others

Osteoporosis

Vitamin D deficiency can contribute to the development of osteoporosis. A 2006 multinational study of 2,600 postmenopausal women with osteoporosis found that 64 percent of the participants had insufficient blood levels of vitamin D. Additionally, in a 2003 study published in the American Journal of Clinical Nutrition, researchers followed 72,000 women for 18 years and found that the women who consumed at least 600 IU per day of vitamin D had a 37 percent lower risk of osteoporosis-related hip fracture than women who consumed less than 140 IU per day. Other clinical trials offer additional evidence that vitamin D supplementation reduces bone density loss and osteoporotic fractures in adults who are deficient.

Current evidence suggests that a minimum daily intake of 600 IU of vitamin D can reduce the incidence of bone decalcification and fractures among the elderly. Those who take supplemental vitamin D to promote bone health and avoid fractures should also ensure an adequate dietary intake of calcium (1,000 to 1,200 milligrams per day). 

Cancer

Scientists have found positive links between vitamin D deficiency and several types of cancer, including breast cancer, prostate cancer and colon cancer. A 2007 study of 1,179 postmenopausal women revealed that participants who took supplements containing 1,100 IU of vitamin D and 1,400 mg of calcium over a period of four years had an overall cancer rate that was 60 percent lower than participants who took only placebos. This clinical trial strongly supports the observational studies that have associated sunlight and vitamin D levels with a lower risk of cancer.

Cardiovascular Disease

Several recent studies offer strong evidence that low vitamin D levels are correlated with the incidence of cardiovascular disease. In a 2008 study published in the Archives of Internal Medicine, researchers compared 454 men (aged 40 to 75) who had a history of heart disease with 900 men who had no history of heart disease. Researchers found that participants with deficient vitamin D levels had a higher risk of heart attack than those with higher vitamin D levels. In another study – one of the most important to date – researchers followed 1,739 members of the Framingham Offspring Study for five years and found that the incidence of cardiovascular disease – including heart attacks, heart failure, and strokes – was from 53 to 80 percent higher in people with low blood levels of vitamin D.

Stroke

According to the American Heart Association, over half a million Americans have a stroke each year. The most common risk factors for stroke include smoking, high blood pressure, lack of exercise and heart disease. But the results of a study published in2008 in the journal Stroke suggest that the incidence of stroke is higher among people with low vitamin D levels, indicating a correlation between low vitamin D levels and stroke. In another study, a Cambridge University neurologist compared blood vitamin D levels of 34 stroke patients with those of 96 healthy volunteers. Results show that the stroke patients’ blood vitamin D levels were a third lower than those of the healthy volunteers.

Vitamin D Facts

Recommended Daily Intake

Adults

Nutritionists once based recommendations for daily vitamin D intake solely on the amount needed to prevent rickets. But because scientists now recognize vitamin D’s role in so many critical physiological functions, experts now recommend 200 IU for adults under 50, 400 IU for adults ages 51 to 70, and 600 IU for adults over 70.

Infants and Children

In 2008, the American Academy of Pediatrics (AAP) revised its recommended daily intake of vitamins D for infants and children to 400 IU. Additionally, the AAP recommends vitamin D supplements for breast-fed and partially breast-fed infants as well as non-breast-fed infants and children who drink less than one liter of vitamin D-fortified milk for formula per day.

Deficiency

Symptoms of Deficiency

Symptoms of vitamin D deficiency include muscle pain, muscle twitching, visual problems, bone pain, anemia, diarrhea, join pain, insomnia, nervousness and a burning sensation in the mouth. If you have any of these symptoms and suspect a deficiency, consult with your physician for proper diagnosis and treatment.

Who’s at Risk?

Several population groups in the United States are at particular risk for vitamin D deficiency. These groups fall broadly into several categories, including people with limited sun exposure, the elderly, people with certain health conditions, exclusively breast-fed infants and people taking certain medications.

Those with limited sun exposure

Sunlight exposure alone provides many with sufficient quantities of vitamin D, but people with dark skin and limited exposure to the sun should be especially careful to ensure adequate vitamin D intake form diet and supplements. People who live in northern latitudes and those who routinely protect themselves from the sun with sunscreen and clothing are especially prone to vitamin D deficiency.

The elderly

As we age, our ability to synthesize vitamin D from sunlight decrease, resulting in lower vitamin D levels. Additionally, the elderly are more likely to spend time indoors and out of the sun. for older adults, the benefits of supplemental vitamin D in preventing disease and prolonging life are especially important.

Those with health conditions

Several health conditions can affect the absorption and metabolism of vitamin D. people with these conditions should consult with their physician to determine appropriate supplementation strategies. These conditions include obesity, fat malabsorption syndromes (such as cystic fibrosis and cholestatic liver disease), inflammatory bowel disease and Crohn’s disease.

Exclusively breast-fed infants

Human milk contains only 25 IU of vitamin D per liter, so exclusively breast-fed infants need supplemental vitamin D to reach the recommended daily intake of 400 IU.

Those taking medications

Certain medications can interfere with vitamin D absorption. These medications include barbiturates, corticosteroids, antacids and statins (cholesterol-lowering drugs). People taking these medications should consider vitamin D supplementation to ensure sufficient intake.

Overall Mortality

An important study in 2008 reveals that inadequate vitamin intake significantly increases overall mortality. In the study, researchers at Johns Hopkins University followed a group of 13,000 initially healthy men and women for more than eight years. During this period, 1,806 people died, including 400 who were deficient in vitamin D. Led author Dr. Michal Melamed summarized the study’s results: “Those who had the lowest levels of vitamin D had a 26 percent higher risk of death from all causes compared to those with the highest vitamin D levels”.

Disease Prevention

Scientists have long recognized the importance of vitamin D in human health, but recent studies have forced the medical world to reevaluate the role vitamin D plays in preventing disease. Dr. Michael F. Holick, director of the Vitamin D, Skin and Bone Research Laboratory at Boston University Medical Center, said, “We know that being vitamin D sufficient reduces the risk of having your first heart attack by more than 50 percent, reduces the risk of having peripheral vascular disease by as much as 80 percent, and decreases the risk of prostate, colon, breast and a whole host of other cancers by as much as 50 to 70 percent”.

Vitamin D

Vitamin D is a fat-soluble vitamin that the human body uses to maintain normal calcium metabolism and promote bone health. The body can synthesize vitamin D when the skin is exposed to ultraviolet radiation from the sun. Vitamin D can also be obtained from both natural food sources and fortified foods. Vitamin D deficiency can create many health problems, and severe vitamin D deficiency results in a condition known as rickets, a debilitating decalcification of the bones. Rickets was common among American children until the 1940s, when the U.S. government began a widespread program to fortify milk with vitamin D.

Today, important new studies have renewed interest in the role vitamin D plays in maintaining health and preventing disease. Scientific evidence associates vitamin D deficiency with an increased incidence of many diseases – including cancer, cardiovascular disease, osteoporosis, stroke, Parkinson’s disease and autoimmune disorders – and suggests that supplemental vitamin D can help prevent these serious health conditions.

New discoveries about vitamin D’s role in human health have been so important that Time magazine named “The Benefits of Vitamin D” as one of the top ten medical breakthroughs of 2007. Adding his perspective to the excitement, interventional nutrition expert Dr. Greg Plotnikoff doesn’t mince words: “Because vitamin D is so cheap and so clearly reduces all-cause mortality, I can say this with great certainty: Vitamin D represents the single most cost-effective medical intervention in the United States”.

Functions

Vitamin D plays a critical role in many physiological processes, including calcium balance, blood pressure regulation, insulin production, cell differentiation and immune system function. Vitamin D’s most important functions involve maintaining normal blood levels of calcium, assisting calcium absorption and building bone mass.

Sources

Vitamin D is available from three basic sources: sunlight, food and supplements. Most people depend on a combination of these sources to meet their needs.

Sunlight

Exposure to sunlight stimulates the epidermis of the skin to produce vitamin D. In fact, many people meet their entire vitamin D requirement by exposure to the sun. however, people with dark skin and those with limited exposure to sunlight need to be especially careful to ensure that their vitamin D needs are met through diet or supplementation.

Food Sources

While most vitamins are found abundantly in many of the foods we eat, food sources of vitamin D are quite limited. The best food sources are egg yolks and oily fish such as salmon, mackerel and sardines. Foods with small amounts of vitamin D include oatmeal, parsley, sweet potatoes and dandelion greens.

Fortified Foods

Because natural food sources of vitamin D are so limited, food manufacturers routinely fortify processed foods with vitamin D. The U.S. government initiated fortification in response to the high incidence of rickets among children in the first half of the twentieth century. In fact, in the 1920s, 75 percent of children in New York Public Schools had some form of rickets. In the 1940s, U.S. dairies began fortifying milk with vitamin D, which led to drastic reductions in the incidence of rickets in the U.S. population.

Today, the foods most commonly fortified with vitamin D include milk, orange juice, yogurt and breakfast cereals. Eight ounces of milk or fortified orange juice contain 100 IU of vitamin D, and a one-cup serving of fortified breakfast cereal contains 40 to 50 IU. Not all breakfast cereals or brands of orange juice are fortified with vitamin D, so it’s important to read the labels to determine exact vitamin D content.

Dietary Supplements

Vitamin D is also available in supplement form, either as part of multivitamin formulas or as an individual supplement. Taking a vitamin D supplement is the easiest and most effective way to ensure an adequate intake of vitamin D.

Multivitamins and Minerals

Manganese

Manganese has received a lot of attention for its role in bone and joint health. Most multivitamins provide only a few milligrams of manganese – enough to satisfy the minimum requirements – but you may want to look for one that provides more than the minimum or consider taking a separate trace mineral supplement.

Benefits of Manganese

  • Promotes normal growth and development
  • Assists enzymes in generating energy
  • Promotes normal cellular function

Chromium

Chromium is important in sugar and lipid metabolism and should be included in any multivitamin formula. However, some manufacturers include far less than the recommended 50 to 200 microgram sin their product’s daily dose. Organically bound chromium is much better absorbed than inorganic chromium chloride.

Benefits of Chromium

  • Assists in the regulation of blood sugar
  • Improves glucose tolerance in people with type 2 diabetes
  • Promotes healthy glucose metabolism

Selenium

Selenium is an important antioxidant cofactor and may be important in cancer prevention. A new RDI has been established at 70 micrograms, but many formulas contain as much as 200 micrograms, which some authorities consider to be in the upper range of recommended intakes.

Benefits of Selenium

  • Acts as a powerful antioxidant
  • Teams up with vitamin E for additional antioxidant properties
  • Promotes normal growth and development

Other Nutrients

Multivitamins vary widely in their nutritional composition. Many include trace minerals such as boron, molybdenum and vanadium. While there are no established recommendations for these nutrients, experts agree that they’re necessary for good health. If your multivitamin doesn’t contain trace minerals, consider taking an occasional trace mineral supplement.

The Bottom Line

If you were to take only one dietary supplement, a good multivitamin would be your best bet. Many of us aren’t getting optimal levels of all the essential nutrients, but a multivitamin can ensure that our nutritional needs are met. The multivitamin / mineral supplement could now replace the apple in a new adage, “A multi a day keeps the doctor away”.

Multivitamin / Mineral Fast Facts

Product forms: Tablets, capsules, liquid, powder and chewables.

Uses and Benefits: Multivitamin supplements prevent nutrient deficiencies and help maintain basic body functions and processes. Multivitamin supplements may also help prevent health conditions such as heart disease, diabetes, cancer and arthritis.

Special Considerations: Always consult with a qualified health care provider before taking a dietary supplement to help treat a specific disease or condition.

Zinc and Copper

Zinc and copper work together in the human body, so a good multivitamin should contain adequate quantities of both. A 15:1 zinc-to-copper ratio is considered ideal, with a range of 10 to 30 parts zinc to one part copper being acceptable.

Benefits of Copper

  • Promotes formation of red blood cells
  • Helps produce enzymes needed for respiration
  • Assists in the formation of hemoglobin in red blood cells

Benefits of Zinc

  • Strong antioxidant properties
  • Helps wound heal
  • Assists in the synthesis of RNA and DNA
  • Promotes the division, repair, and growth of cells

Potassium

Multivitamin often include potassium at doses around 100 milligram per tablet, far below the recommended intake of 3,000 milligrams or more. However, individuals with varied, healthful diets usually don’t have a problem obtaining adequate amounts of potassium.

Benefits of Potassium

  • Promotes regular heartbeat
  • Maintains water balance in body tissues
  • Support normal muscle contraction
  • Treats drug-induced potassium deficiency
  • Promotes transfer of nutrients to cells