By Philip S. Chua, M.D., FACS, FPCS
What is this vitamin?
The sunshine vitamin is vitamin D, the only vitamin humans can produce on their own, when exposed to the ultraviolet B from the sun. In 15 minutes, a fair-skinned person, outside on a sunny day, can generate as much as 10,000 to 20,000 IU of vitamin D. This vitamin is recently in the limelight for being a “blockbuster” nutrient that confers even greater health benefits than previously recognized by the medical community. This “re-discovery” has put vitamin D in an altogether new perspective and importance.
What foods contain vitamin D?
Not many foods contain vitamin D. Milk is fortified with 125 IU of vitamin per glass. The following contain some vitamin D, but in themselves, do not provide the minimum daily requirement: organ meats, eggs, fish like sardines, salmon, and herring. Having a balanced diet with enough calcium (1000-1500 mg) and vitamin D (400 IU daily) will prevent osteoporosis (thinning of the bones, a common cause of fractures). Exposure to the sun for about 5-10 minutes, 2-3 times a week is enough help in the body’s production of vitamin D.
How different is D from the other vitamins?
Besides being unique in the sense that it is the only vitamin our body can make on its own, vitamin D is also the only vitamin that influences the entire body, as the findings have shown. Receptors that respond to vitamin D have been discovered in almost all the various kinds of human cells, from the brain to the bones.
What else is vitamin D good for?
Besides the old role vitamin D was popular for (boosting absorption of calcium which is essential for bone health), vitamin D has also been found over the past decades, especially the last 8 years, to have a broad range of added benefits.
This includes the ability to help fight cancers and diabetes. Sixty-three independent studies showed that high normal level of vitamin D reduced the risk of developing colon, breast and ovarian cancer by 50%. It is also a “pivotal feedstock” for a hormone that protects muscles, and inhibits autoimmune diseases like multiple sclerosis, lupus and inflammatory bowel illnesses. It also helps in easing some body aches and pain.
Does vitamin D deficiency still exist?
In spite of the fact that our own body produces vitamin D upon exposure to the sun, vitamin D deficiency still exists and is actually an unrecognized epidemic worldwide, especially among those 5o and older. In the USA, the FDA is calling for a revision of its vitamin D recommendation because it is outdated. The present FDA suggestion of 200 IU daily for people under 51, and 400 IU for those who are older, is now considered obsolete. Researchers recommend 1,000 IU daily for all ages, and perhaps as high as 2,000 IU.
What causes the deficiency?
Avoidance of sun exposure and inadequate dietary vitamin D intake are the usual causes, which factors could lead to the development of a medical condition called Rickets (the metabolic bone disease in children, called osetomalacia in adult). In the tropics, or even in a country like the USA, infants who are swaddled and people confined to indoors are at high risk of vitamin D deficiency for lack of exposure to sunlight. Low milk intake and eating cereals and food not fortified with calcium and phosphorus are also possible contributing factors. Defects in the production of 25(OH)D3 (vitamin D3), or the action of 1,25(OH)2D3, hypoparathyroidism, or hereditary disease called familial hypphosphatemic rickets may cause vitamin D deficiency. Diseases that interfere with the production, metabolism, or absorption of vitamin D may also cause the D deficiency.
How does one prevent vitamin D deficiency?
Health education and awareness are essential. Human breast milk does have enough vitamin D (40 IU/L), unlike fortified cow’s milk (400 IU/L). Babies who are breastfed should have an oral supplement of vitamin D (300 IU per day) from birth to 6 months. Dr. Michael F. Hollick of the Boston University School of Medicine stated in their NIH-funded study, which involved 16,500 subjects, they have “found that lactating women need about 6,000 IU a day to transfer enough vitamin D into their milk to supply adequate amount to a nursing infant.” In more urgent cases, like the studies done among adolescents in the Far East, one does of intramuscular injection of 2.5 mg (100,000 IU) of ergocalciferol given in the Fall has increased the plasma level of vitamin D that lasted till Spring the following year.