Most of us know that vitamin D is important for bone health, but this essential nutrient has other benefits, too. Over 900 genes and several areas in the body—the brain, heart, blood vessels, muscles and intestines—have vitamin D receptors, or proteins that bind to vitamin D.

Studies show positive health effects happen when vitamin D binds to these receptors. Perhaps that’s why research indicates vitamin D’s role in immune, cellular, brain and cardiovascular health.

Let’s take a closer look at what the research is saying:

• Immune support. Vitamin D is a powerful immune system supporter and inhibits negative autoimmune responses by modulating cell responses. When vitamin D is in short supply, cells can attack the body instead of fighting off unwanted invaders.
• Cell proliferation and differentiation. When certain cells divide rapidly, or proliferate, the impact on your health can be devastating. Cell differentiation, however, can decrease unwanted proliferations. Vitamin D inhibits unwanted proliferation and stimulates healthy cell differentiation. Lung, skin, colon, bone and breast sites have been studied for vitamin D’s positive effects on cell differentiation and proliferation, causing them to act as normal, mature cells.
• Brain health. Scientists at the Children’s Hospital & Research Center Oakland in Oakland, California, say the brain has a wide distribution of vitamin D receptors wherein vitamin D directly and positively affects learning, memory, motor control and attention. Vitamin D protects and maintains healthy brain cells, while a deficiency can result in brain dysfunction.
• Cardiovascular health. Vitamin D may play a role in cardiovascular health since low blood levels of vitamin D can increase coronary artery calcification. Vitamin D deficiencies can also elevate risk of stroke and congestive heart failure, while optimal vitamin D levels support normal levels of inflammation—important for cardiovascular health.

The key for these benefits is to get enough vitamin D, but many people are deficient. Those at risk for a vitamin D deficiency include breastfed infants, dark-skinned individuals, those with fat malabsorption challenges, and the obese. People aged 50 and up are at risk, too. Why? As people age, the skin can’t synthesize vitamin D as efficiently as it once did.

Those with limited sun exposure can fall short on vitamin D, too. People who work inside, homebound individuals, those avoiding the sun due to skin cancer concerns and those living in northern latitudes—basically those who reside north of an imaginary line that runs from the northern border of California all the way to Boston—are particularly at risk.

How much vitamin D is enough? That’s a good question that doesn’t have an open-and-shut answer. Most experts agree, however, that we need to boost our vitamin D intake.

Our nation’s leading pediatrician group, the American Academy of Pediatrics, recommends children from birth to their teen years increase vitamin D intakes to 400IU daily—twice as much as the 200IU recommended in 2003. Millions of children should take daily vitamin D supplements to meet the requirements, says the American Academy of Pediatrics.

Adults aged 51 to 70 are recommended to get 400IU daily, while those 71 and up should get 600IU daily. The Institute of Medicine, the government advisory group setting these dietary guidelines, may change recommendations due to emerging research indicating we could require more.

Many experts recommend between 800 to 1,000IU for adults, but some believe 2,000IU of vitamin D daily will provide maximum benefits. That means we may need to supplement and demand more from our diets. Cod liver oil, pink salmon, mackerel, sardines and tuna are excellent vitamin D-packed foods.