Vitamin D is a important vitamin that you get through some of the foods you eat and through exposure to the sun. When the skin is exposed to the sun, it can produce vitamin D. Vitamin D is also available as a dietary supplement.
- Helps build bone and absorb calcium, which is also essential for healthy bones.
- Reduces inflammation.
- Can help prevent muscle cramps and spasms.
- Supports a healthy immune system. It can reduce your risk of getting a viral infection like the flu and lower the severity of an infection if you fall ill, says registered dietitian Sonya Angelone, a San Francisco area-based spokeswoman for the Academy of Nutrition and Dietetics.
- Some health experts believe that vitamin D may reduce the risk of certain types of cancer, such as colorectal cancer. Research in this area is underway.
There are two types of vitamin D that are important for humans: D2 are from plant-based sources, and D3 produced by the body when the skin is not protected by sunscreen and exposed to ultraviolet rays in sunlight.
The recommended daily dose of vitamin D for children and adults is 600 IU (15 mcg) up to 70 years. From age 70, the RDA is 800 IU (20 mcg). In infants up to one year of age, RDA is 400 IU. All of these RDAs assume that a person gets minimal sun exposure, but federal guidelines do not specify how much sun exposure that means.
Vitamin D deficiency is common
Many Americans are thought to be deficient in vitamin D. A 2012 report from the Centers for Disease Control and Prevention says that 8.1% of Americans are deficient in vitamin D, although other studies and estimates mention a much higher percentage. In the CDC study, the highest deficiency was found among black people, with 31% found to be vitamin D deficiency.
On average, it is estimated that older adults receive 160 to 400 IU daily of vitamin D, which rises to 300 to 900 IU daily when supplements are used, according to dietary references for calcium and vitamin D from the National Academies of Science, Engineering and Medicine.
There are a few reasons why people may not get enough vitamin D:
- It is not often found in food sources.
- Although you can get vitamin D from the sun, many of us do not get much outdoor exposure due to work that limits us indoors. In addition, many people use sunscreen to protect their skin from harmful UV rays. Plus, if you live further away from the equator, you probably have less exposure to sunlight, says Michelle Bauche, a clinical dietitian with the Weight Management and Metabolic Institute at the University of Missouri Health Care in Columbia.
- Some people have gene variants that make it difficult for their bodies to produce vitamin D, even though their skin is exposed to ultraviolet light.
There is also a broad section of the population that often has vitamin D deficiency. These subgroups include:
- Older Americans. It is harder to absorb vitamin D as you get older. This is one of the reasons why higher levels of vitamin D are recommended for adults aged 70 years or older.
- Those who have indoor jobs because they are not much out in the sun, says Antonette Hardie, a registered dietitian at Ohio State University Wexner Medical Center in Columbus.
- Those who have darker skin.
- Those with inflammatory bowel disease or cystic fibrosis because these diseases make it harder for the body to absorb vitamin D.
- Those who are vegan or lactose tolerant and certain types of vegetarians may struggle to get enough vitamin D, Hardie says. This is because the food sources that supply vitamin D often come from animals, such as dairy products and fish.
- Those who are overweight. Body fat can isolate vitamin D instead of spreading it to other parts of the body, says registered dietitian Ali Webster, director of research and nutrition communication at the International Food Information Council in Washington, DC. Obesity is considered a body mass index of 30 kg / m2 or higher.
- Breastfeeding infants. This is because breast milk is not a good source of vitamin D, and infants should not be exposed directly to the sun, Webster says. Breast-feeding infants should receive a 400 IU vitamin D supplement a day until they can consume 1,000 milliliters of vitamin D-enriched formula or whole cow’s milk daily, according to the American Academy of Pediatrics.
Signs of vitamin D deficiency
There are several signs of vitamin D deficiency, including:
- Bone pain.
- More frequent infections and diseases.
- Low back pain.
- Mood swings.
- Muscle pain or cramps.
- A softening of the bones that presents as rickets in children and as osteomalacia in adults, Bauche says.
- Chronic vitamin D deficiency can put you at a higher risk for fractures and osteoporosis, Webster says.
Of course, the same signs can be associated with many other health problems, such as stress, dehydration, or sore joints caused by weather changes, Hardie says. If you have these signs and suspect that they are associated with vitamin D deficiency, talk to your healthcare provider about getting a blood test that can check for vitamin D deficiency.
A normal level from a vitamin D lab test is usually considered to be 20 to 40 ng / ml, but some healthcare providers like to see levels closer to 30 to 50 ng / ml.
What should I do if you have vitamin D deficiency?
If a lab test indicates you are not getting enough vitamin D, there are a few things you can do.
Turn first for food. Some good food sources for vitamin D include:
- Oily fish such as salmon. A three-ounce serving of sockeye salmon provides 71% of the RDA for vitamin D.
- Dairy products and non-dairy products, which are usually fortified with vitamin D. A cup of 2% cow’s milk provides 15% of vitamin D, which children and adults need daily. For non-dairy milk, a cup provides 13% to 18% of an adult’s RDA for vitamin D.
- Egg. An egg has 6% of the RDA for vitamin D.
- Liver. Three ounces of liver provides 5% of the RDA for vitamin D.
- Fungi are a potential source of vitamin D, but the amount of vitamin D they have increases if they have been exposed to UV light in the growth process. For example, half a cup of portabella mushrooms have only 1% of the RDA for vitamin D, but when exposed to UV light, it spikes to 120% according to the Mushroom Council. Look on the packaging for a note indicating that the fungi have been treated with UV light.
- Orange juice and grains enriched with vitamin D. A serving of grains of regular size usually provides 10% of the daily value needed for vitamin D.
Eating a well-rounded, overall healthy diet can help you get more vitamin D, Hardie says.
Next, aim to get just a few minutes of sunlight a day. After all, vitamin D is often called sunshine vitamin. However, this sunscreen requires only a little bit of sun protection – 10 to 15 minutes a day should be enough, with some of your skin (like your arms or legs) exposed.
However, the American Academy of Dermatology advises people to get their vitamin D from food sources, not the sun.
A third option instead of or in addition to exposure to food and sun is a dietary supplement. This is best done in collaboration with your healthcare provider, who can help decide the right dosage for you. Generally, 1,000 to 5,000 IU is considered safe, Bauche says. These higher doses are used because many people do not absorb all of the vitamin D that their body receives, Angelone says. Some people get vitamin D prescriptions of up to 50,000 IU weekly. You can use either D2 or D3 supplements, although D3 Dietary supplements are more common.
A few tips to help choose a good vitamin D supplement:
- Find out if a supplement will interact with the drugs you are using. For example, the cholesterol-lowering drug cholestyramine may reduce your absorption of vitamin D.
- Look for a supplement with a USP seal. This indicates that the product has been verified for its purity, potency and production quality by the US Pharmacopoeia. This is an important step because dietary supplements are not regulated by the Food and Drug Administration, warns Webster.
- Buy directly from the manufacturer. Dietary supplements offered by third-party distributors may not be stored under ideal conditions or may be counterfeit, Bauche warns.
- Ask your healthcare provider if you need to use other supplements with vitamin D, Advises Angelone. Some health experts want you to use vitamin K2 or magnesium along with vitamin D to help your body absorb vitamin D better.