If you haven't noticed, vitamin D is all over the news because we continue to learn more and more about it and its interactions in the body. Unlike other vitamins, we are still learning new things about vitamin D all the time because it acts more like a hormone than a vitamin. Its deficiency in the body has severe repercussions, the extent of which we continue to learn and appreciate. In fact, it was reported recently in Alternative Medicine Review (March 2008) that the first RCT [randomized clinical trial] of vitamin D in preventing internal cancers found a 60-percent reduction in such cancers by increasing baseline 25(OH)D levels [the lab test for vitamin D] from 29 ng/mL to 38 ng/mL with 1,100 IU (28 mcg) per day. In other words, increasing vitamin D levels helped to prevent certain cancers.

They went on to report that, "Besides cancer, vitamin D deficiency is associated with cardiovascular disease, hypertension, stroke, diabetes, multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, osteoporosis, periodontal disease, macular degeneration, mental illness, propensity to fall, and chronic pain. A recent review presented considerable evidence that influenza epidemics, and perhaps even the common cold, are brought on by seasonal deficiencies in antimicrobial peptides (AMP), such as cathelicidin, secondary to seasonal deficiencies in vitamin D. Results of an RCT support the theory, finding 2,000 IU of vitamin D/day for one year virtually eliminated self-reported incidence of colds and influenza. Even the current triple childhood epidemics of autism, asthma, and type 1 diabetes, all of which blossomed after sun-avoidance advice became widespread, might be the tragic and iatrogenic sequela of gestational or early childhood vitamin D deficiencies brought on by medical advice to avoid the sun."

Furthermore, a report published in the Journal of Clinical Endocrinology and Metabolism, March 2009, reported that mother's sun exposure may affect kids' bone growth.

NEW YORK (Reuters Health) - Women who get some sun during the last trimester of pregnancy may have children with stronger bones, a new study suggests.

UK researchers found that among nearly 7,000 10-year-olds they assessed, those whose mothers were in their last trimester during sunny months tended to have larger bones.

The connection, the researchers say, is presumably explained by vitamin D, which is synthesized in the skin after sun exposure and plays a key role in bone health.

It's possible that mothers' vitamin D levels late in pregnancy have lasting effects on their children's later bone development, the researchers report in the Journal of Clinical Endocrinology and Metabolism.

No one is recommending that pregnant women bask in the sun. Too much UV exposure is a known risk factor for skin cancer.

However, the findings do offer "further justification for strategies intended to improve maternal vitamin D status to optimize skeletal health the child," write researchers Adrian Sayers and Jonathan H. Tobias of the University of Bristol.

Milk and breakfast cereals fortified with vitamin D are among the main food sources of the vitamin. Few foods naturally contain vitamin D, though some fish, like salmon, mackerel and tuna, contain substantial amounts.

Currently, the official recommendation for vitamin D during pregnancy is 200 IU per day, though researchers are still trying to determine what the optimal intake is. A number of studies have suggested that vitamin D deficiency is common in pregnant women.

These latest findings are based on 6,995 British children who underwent bone scans as part of a long-term health study. The researchers used local meteorological data to estimate the mothers' UV exposure during their last trimester.

In general, the study found, children whose mothers had greater sun exposure tended to have larger bones than those whose mothers had less sun exposure.

Bone mass acquired earlier in life is important to fracture risk in later years. If the benefits seen in this study persist into adulthood, Sayers and Tobias note, mothers' vitamin D levels during pregnancy might affect their children's bone health into old age.

Vitamin D deficiency is easy to detect and easy to fix. More about that on Wednesday.