Vitamin D is involved in so many key bodily functions that it’s difficult to pinpoint the symptoms of insufficiency.
Adequate levels are not only needed for calcium balance and strong bones but may also play important roles in cell growth, neuromuscular health, immune function and reducing inflammation. If that’s not grand enough, vitamin D may help in the fight against diabetes, heart disease and cancer. Emerging science caused experts in the U.K. to reconsider the cutoff for adequate levels, moving it higher. Clinical trials are planned to shed more light on the data, but for now there are many reasons to make sure you’re getting enough.
The vitamin is produced in the skin of humans and animals during prolonged sun exposure, and some experts say you’d have to sunbathe outside in a bathing suit for 15 to 30 minutes every day to glean the natural benefits. “Throughout history, the main source of vitamin D has been the body's own production once skin is exposed to sunlight, but more recently milk and other fortified foods have provided significant amounts because humans are largely deficient,” says rheumatologist James E. Dowd, M.D., associate clinical professor of medicine at Michigan State University and author of “The Vitamin D Cure” (John Wiley & Sons).
Dowd says you're most likely deficient if you don’t get enough vitamin D in your diet and if you live far away from the equator where sunlight is especially weak during the winter. In that case, you’ll need to get plenty of vitamin D from foods and spend more time outdoors. You’re also more prone to vitamin D deficiency if you’re dark-skinned, Hispanic or African-American since darker complexions require more sun exposure to synthesize the nutrient.
The elderly and chronically ill and obese individuals are thought to be especially at risk for low vitamin D, at least in part because they tend not to be physically active outdoors. Certain medications and a variety of other medical conditions can also diminish a person’s vitamin D levels. Vitamin D as it relates to calcium and bone strength is a special consideration in the elderly because of the risk of falls and fractures.
How do you spot a deficiency?
During your annual physical, a health-care provider can perform a simple in-office blood test to see if your vitamin D levels are adequate, or if you should supplement or tweak your lifestyle habits to absorb more of this vital nutrient. The test may or may not be covered by insurance.
The general dietary reference intake for adults is 600 International Units per day, but seniors over age 70 should take 800 IU. Optimal levels of vitamin D and supplemental doses continue to be debated and discussed by experts. If you’ve been told you’re low, Dowd recommends taking 20 IU of vitamin D3 (not D2) per pound of body weight daily, or about 3,000 to 5,000 IU per day, to get into normal range. “Too much D in your blood is just as dangerous as having too little, but this is very rare,” he says.
Tracking the subtlest symptoms
Vitamin D plays such a central role in overall health and well-being that patients and caregivers should be alert to the possibility of a deficiency. A large portion of the general population may not be getting enough vitamin D through sun exposure and diet alone. As an individual’s levels decline, symptoms like these will become more noticeable:
- General weakness
- Muscle weakness
- Muscle pain
- Widespread pain and depressive symptoms
- Rickets in children
Osteopenia and osteoporosis are indications that you may lack vitamin D. At your next checkup, request the 25-hydroxyvitamin D test, and don’t eat anything for at least four hours beforehand, Dowd advises. “Your risk of disease increases if your blood levels of vitamin D are below 30 nanograms per millimeter (ng/ml); between 40 and 60 is ideal,” he says. Once you know you’re lacking vitamin D, daily supplementation in pill form will bring levels back to the recommended range.
Sometimes it’s hard to tell whether low vitamin D is the cause or the effect of disability and illness but research shows an association between lower vitamin D levels and greater mortality. In one study, most of these deaths were related to heart attack and stroke, so caregivers should be on the lookout for signs of vitamin D deficiency in their loved ones.
It isn’t clear whether time in the sun is always enough to overcome a poor diet. To be on the safe side, choose dietary sources of vitamin D including animal meats, eggs, fish oil, canned salmon and dairy products, says Keri Glassman, M.S., R.D, president of A Nutritious Life in New York City. Because the elderly, the obese and people who suffer from gastrointestinal disorders and kidney disease have a harder time making and absorbing vitamin D, they may need to supplement.
Take the next steps
Here are several other strategies to help you and your family get the vitamin D you need:
Examine your diet. If you don’t consume enough foods that contain this vitamin, you’re at risk of deficiency. Vegans have been shown to be largely vitamin D deficient and should opt for fortified cereals and energy bars that are enriched with vitamin D. If you eat egg yolks, cultured soy and kefir daily, you’re in good shape, says Glassman.
Lose weight. Being obese or overweight is another risk factor for deficiency. Heavier individuals may not consume enough vitamin D in their diets and may spend less time being physically active outdoors, making it difficult to lose weight. People with Crohn's disease or celiac disease may not be able to metabolize vitamin D properly, so discuss these and other conditions with your health practitioner.
Try supplements. A vitamin D deficiency can cause mood swings and exacerbate PMS symptoms, says Glassman. She recommends having supplements and herbal remedies on hand. “It makes some sense to sit in the sun unprotected for 15 minutes a few times a week, but head outside after the strongest sun of the day,” she suggests.
If it’s difficult for you to swallow a daily supplement in pill or capsule form, you’ll be glad to know that many new cosmetics contain vitamin D in foundations and moisturizers, Glassman says. There’s even a vitamin D powder to sprinkle on salads and soups to help you get your daily dose. Sunshine not included.