Vitamin Information Center

The human body is an amazing factory, with all kinds of parts working together to make chemicals necessary for good health. But one thing it can’t make on its own is vitamin D. Research shows that defect can be troubling, especially among children.

To create vitamin D, which plays an important role in bone health and development, the body needs exposure to sunlight. As some countries move into autumn, the days get shorter and colder and exposure to sunlight decreases, making the colder months of the year a crucial time to watch vitamin D intake. Supplements can play an important role but one question is, how much?

Most of a child’s bone mass is built up early. A vitamin deficiency can prevent a child from building adequate bone mass now, and they won’t be able to make it all up later.

Although a study released this week found that vitamin D deficiencies are common in children around the world, there is minimal data on how much supplementation is necessary or safe.

Vitamin D is a fat — soluble vitamin directly or indirectly involved in several key body processes: regulating calcium and phosphorus levels in the blood, promoting bone formation and mineralisation, restricting parathyroid hormone secretion and promoting anti-tumour activity.

A review of medical literature on the vitamin published last year in The New England Journal of Medicine found that vitamin D is also associated with a reduced risk of type 1 diabetes in children, and may inhibit future hip fracture.

The main source of vitamin D is sunlight, which the body uses to convert vitamin D into a useable form. It’s also found naturally in eggs and fatty fish like salmon or tuna, and milk and some breakfast cereals are fortified with the vitamin.

The Institute of Medicine recommends that children get 200 IUs of vitamin D daily, but some experts say that up to 800 IUs is better.

The new study found that high doses of the vitamin were safe for children, whether taken over the short-term or for a longer period of time, and helped increased bone mass in 10 to 17 year olds.

A study released this summer found that even children who are otherwise healthy can have low levels of vitamin D, resulting in low levels of bone mineral content.

The risk for low vitamin D levels begins in infancy —breast milk, like cow’s milk, is naturally low in vitamin D. And if a mother doesn’t have enough vitamin D, her breast milk won’t either.

A vitamin D deficiency can affect bone growth even if there are no obvious problems.

A bottle of vitamin supplements
The American Academy of Paediatrics says that rickets, bone softening that can lead to fractures and deformity, in infants due to low vitamin D intake is seen in several US states.

The agency recommends that breast-fed infants receive vitamin D supplement drops.

Children at risk
“It is recommended that all infants, including those who are exclusively breastfed, have a minimum intake of 200 IUs of vitamin D per day beginning during the first two months of life,” said a clinical report for the health agency done by Dr Lawrence Gartner and Dr Frank Greer.

“In addition, it is recommended that an intake of 200 IUs of vitamin D per day be continued throughout childhood and adolescence, because adequate sunlight exposure is not easily determined for a given individual.”

The risks to bone health don’t end in infancy.
A Canadian study released last year found that despite guidelines for its prevention, vitamin D-deficiency rickets in childhood is still seen in the country, with an annual incidence of 2.9 cases per 100,000.

Children living in countries where exposure to sunlight is low had the highest incidence, and most of the affected children had medium to dark skin tones and had been breast fed.

“Since there were no reported cases of breast-fed children having received regular vitamin D (400 IU/d) from birth who developed rickets, the current guidelines for rickets prevention can be effective but are not being consistently implemented,” the study concluded.

Adequate vitamin D levels in the blood are important because the body can’t absorb dietary calcium without vitamin D, so in its absence it steals calcium from the bones, which increases the risk of rickets, osteoporosis and fractures.

This also places teenagers at risk because they have weaker bones that are more likely to fracture.

Children at particular risk include infants who are breast-fed exclusively and don’t receive supplementation, children who use sunscreen in summer, children who don’t use sunscreen in the summer but spend less than 15 minutes a day in direct sunlight, children who receive no supplementation in the winter, and children with chronic diseases that affect fat malabsorption, such as cystic fibrosis or celiac disease, according to the Hospital for Sick Children.

TORONTO (Reuters) - The human body is an amazing factory, with all kinds of parts working together to the make the chemicals necessary for good health. But one thing it can’t make on its own is vitamin D. Research shows that defect can be troubling, especially among children.

To create vitamin D, which plays an important role in bone health and development, the body needs exposure to sunlight. As we move into autumn, the days get shorter and colder and our exposure to sunlight decreases, making the colder months of the year a crucial time to watch vitamin D intake. Supplements can play an important role but one question is, how much?

Most of a child’s bone mass is built up early. A vitamin deficiency can prevent a child from building adequate bone mass now, and they won’t be able to make it all up later. Although a study released this week found that vitamin D deficiencies are common in children around the world, there is minimal data on how much supplementation is necessary or safe.

Vitamin D is a fat-soluble vitamin directly or indirectly involved in several key body processes: regulating calcium and phosphorus levels in the blood, promoting bone formation and mineralization, restricting parathyroid hormone secretion and promoting anti-tumor activity. A review of medical literature on the vitamin published last year in The New England Journal of Medicine found that vitamin D is also associated with a reduced risk of type 1 diabetes in children, and may inhibit future hip fracture.

The main source of vitamin D is sunlight, which the body uses to convert vitamin D into a useable form. It’s also found naturally in eggs and fatty fish like salmon or tuna, and milk and some breakfast cereals are fortified with the vitamin. The Institute of Medicine recommends that children get 200 IUs of vitamin D daily, but some experts say that up to 800 IUs is better.

This week’s study found that high doses of the vitamin were safe for children, whether taken over the short-term or for a longer period of time, and helped increased bone mass in 10-17-year olds.

Vitamin D deficiency is particularly a problem for North Americans, research shows, due in part to the higher latitudes at which they live. As well, because of concerns about skin cancer, many people now wear sunscreen, which inhibits the body’s ability to use sunlight to make the vitamin. The Hospital for Sick Children in Toronto says that sunscreen with an SPF above 8 blocks all vitamin D production through the skin. And darker-skinned individuals living in Canada and the United States may be at particular risk because they have more melanin in their skin, which means they need more sunlight than a lighter-skinned person to make the same amount of vitamin D.

A study released this summer found that even children who are otherwise healthy can have low levels of vitamin D, and resulting low levels of bone mineral content. More than 12 percent of the 400 kids studied by researchers at the Children’s Hospital in Boston had levels of vitamin D in their blood low enough to qualify them as deficient, and 40 percent of the children had less than the recommended level
The risk for low vitamin D levels begins in infancy - breast milk, like cow’s milk, is naturally low in vitamin D. And if a mother doesn’t have enough vitamin D, her breast milk won’t either.

A vitamin D deficiency can affect bone growth even if there are no obvious problems. The American Academy of Pediatrics says that rickets (), bone softening that can lead to fractures and deformity, in infants due to low vitamin D intake is seen in several U.S. states. The agency recommends that breast-fed infants receive vitamin D supplement drops.

“It is recommended that all infants, including those who are exclusively breastfed, have a minimum intake of 200 IUs of vitamin D per day beginning during the first 2 months of life,” said a clinical report for the health agency done by Drs. Lawrence Gartner and Frank Greer. “In addition, it is recommended that an intake of 200 IUs of vitamin D per day be continued throughout childhood and adolescence, because adequate sunlight exposure is not easily determined for a given individual.”

The risks to bone health don’t end in infancy. A Canadian study released last year found that despite guidelines for its prevention, vitamin D-deficiency rickets in childhood is still seen in the country, with an annual incidence of 2.9 cases per 100,000. Children living in the northern part of the country, where exposure to sunlight is the lowest, had the highest incidence, and most of the affected children had medium to dark skin tones and had been breast fed.

“Since there were no reported cases of breast-fed children having received regular vitamin D (400 IU/d) from birth who developed rickets, the current guidelines for rickets prevention can be effective but are not being consistently implemented,” the study concluded.

Adequate vitamin D levels in the blood are important because the body can’t absorb dietary calcium without vitamin D, so in its absence it steals calcium from the bones, which increases the risk of rickets, osteoporosis and fractures. This also places teenagers at risk because they have weaker bones that are more likely to fracture.

Children at particular risk include infants who are breast-fed exclusively and don’t receive supplementation, children who use sunscreen in the summer, children who don’t use sunscreen in the summer but spend less than 15 minutes a day in direct sunlight, children who receive no supplementation in the winter, and children with chronic diseases that affect fat malabsorption, such as cystic fibrosis or celiac disease, according to the Hospital for Sick Children.

Because natural sources are so rare, it’s difficult to get adequate vitamin D in the diet. One tablespoon of cod liver oil has 1,360 IUs, a serving of cooked salmon has 360, a cup of fortified milk has 98 and a whole egg has 20. Fifteen minutes of direct sunlight is enough for many people to reach their needs for vitamin D, but darker-skinned people need longer exposure and because winter sunlight in North America is indirect, supplementation may be recommended.

Do you supplement with extra vitamin D? Let us know: HealthMatters@reuters.com

Low vitamin D levels are associated with a higher risk of death, according to a report released on August 11, 2008 in the Archives of Internal Medicine, one of the JAMA/Archives journals.

Vitamin D is a group of prohormones that play important roles in calcium metabolism, bone formation, parathyroid function, and the immune system. Presently, the ideal bood levels of 25-hydroxyvitamin D (25[OH]D) has been suggested as 30 nanograms per milliliter or higher. In the United States, approximately 41% of men and 53% of women have levels lower than 28 nanograms per milliliter.

There are many potential health problems that could contribute to death in individuals with low vitamin D levels, including an effect on blood pressure, insulin response, or risk of obesity and diabetes.

To investigate the potential implications of this deficiency, Michal L. Melamed, M.D., M.H.S., of the Albert Einstein College of Medicine, Bronx, N.Y., and colleagues examined 13,331 individuals in the Third National Health and Nutritional Examination Survey (NHANES III), a large cohort study performed by the Centers for Disease Control and Prevention (CDC). These individuals were examined for Vitamin D levels between 1988 and 1994, and tracked through 2000, with a median 8.7 years of follow-up.

In this period, 1,806 participants died. When divided into groups based on vitamin D levels, the group maintaining the lowest level, defined as less than 17.8 nanograms per milliliter, showed a 26% increased risk of death from any cause in comparison with the group with the highest levels of vitamin D. This was not associated with cardiovascular disease or cancer alone.

The authors conclude that “the lowest 25(OH)D quartile (less than 17.8 nanograms per milliliter) is associated with a higher risk of all-cause mortality in the general U.S. population.” They continue: “Further observational studies are needed to confirm these findings and establish the mechanisms underlying these observations. If confirmed, randomized clinical trials will be needed to determine whether vitamin D supplementation at higher doses could have any potential benefit in reducing future mortality risk in those with 25(OH)D deficiency.”

25-Hydroxyvitamin D Levels and the Risk of Mortality in the General Population
Michal L. Melamed, MD, MHS; Erin D. Michos, MD, MHS; Wendy Post, MD, MS; Brad Astor, PhD
Arch Intern Med. 2008;168(15):1629-1637
Click Here For Abstract

Written by Anna Sophia McKenney
Copyright: Medical News Today