Vitamin D known for playing a key role in bone health, as without it the body unable to absorb calcium, increasing the risk of osteoporosis and fractures, which is why it appears to be shaping up as the nutrient of the year, if not the decade.

However, evidence linking vitamin D deficiency to many other health problems continue to accumulate. Last year alone, higher levels of vitamin D have been linked with lower susceptibility to colds and flu, a reduced risk of fracture, better brain function, including lower percentage of body fat in women.

Despite, the growing body of evidence that vitamin D makes a vital contribution to good health as we age, over 1/10 of older adults appear to have low levels of vitamin D, associated with higher risks for various diseases, with just a few having optimum levels.

The presence of vitamin D receptors all over the body in the joints, muscles, brain and other organs, means low vitamin D levels have a systemic effect, including also being linked with colon and breast cancer, a weakened immune system and poorer brain function.

Most experts have found strong enough evidence to raise the recommended daily intake of vitamin D to 800 IU (international units), which is high enough to prevent deficiency even in those who get little or no vitamin D via sunlight. While, this level is sufficient for strengthening bones and muscles, it is not certain it is enough to ward off chronic disease.

• Vitamin D is essential for bone health, as bone-building minerals calcium and phosphorus rely on vitamin D for absorption. A review of 167 studies indicates people getting a minimum of 700 IU of the vitamin and who took calcium pills had denser bones and fewer fractures, compared to those taking only vitamin D supplements.

• Deficiency in vitamin D decreases muscular strength and performance.

• By regulating cell growth, vitamin D helps regulate cell growth, inhibiting the formation or spread of cancer cells. A deficiency of the vitamin is linked to an increased risk of breast, colon, and prostate cancer, including higher mortalities from them.

• Low levels of vitamin D result in cardiovascular disease, inflaming the coronary arteries, which has been linked to increased risk of heart attack.

• Vitamin D deficiencies weaken the body’s response to infection, and as levels go down, the risk of rheumatoid arthritis goes up. Deficiency of vitamin D has also been linked to an increased risk of insulin resistance or type
1 diabetes, including higher blood levels of vitamin D being associated with a reduced risk of multiple sclerosis.

• Low levels of vitamin D raises the risk of depression, including reduced cognitive performance in older 65 plus adults.

To get sufficient amounts of the sunshine vitamin manufactured by the skin, exposure to the UVB rays of the sun is essential. The skin’s ability to convert UVB rays into vitamin D declines as we age, while dark-skinned individuals do not readily absorb UVB rays, leaving them at a higher risk for vitamin D deficiency. To use the sun as a source of vitamin D, one must get out into the sun thrice a week for a minimum of 15 minutes, with 10:00 a. m. to 2:00 p. m. being the best time.

As there are few vitamin D rich foods, most foods like dairy products, breakfast cereals, orange juices, soy-based foods are fortified with the vitamin.

The daily recommendation of vitamin D is around 1,000 IU a day, with 2,000 IU being the upper limit.

A review article in the January 2008 edition of American Journal of Clinical Nutrition concluded 10,000 IU of vitamin D a day is not toxic. While, experts don’t recommend that much, even if you get over 2,000 IU a day, there is no need to worry.