Vitamin D
I wish to review with you the topic on Vitamin D. This was lectured to us extensively by Dr Maria Imelda Belen Vitug Sales, a pediatric gastroenterologist.
According to Dr Sales, Vitamin D is technically not a vitamin. Since, vitamins have to be consumed as they cannot be created in the body. Vitamin D is better classified as a hormone or a pre – hormone because it has to be converted to its active hormonal component.
Furthermore, Vitamin D, regulates the activity of over 200 different genes. Dr Sales said that most circulating vitamin D is synthesised endogenously from skin exposure to ultraviolet B radiation and that skin synthesis is influenced by the following:
– skin pigmentation
– sunscreen
– latitude
– season
– clothing
– indoor time
– air pollution
– and urbanization
Ultraviolet B availability is blocked by glass, by clouds and SPF >8. And the peak of UVB availability is between 10 am to 3pm.
There are 4 different forms if Vit D and these are:
1. Vitamin D2 is also called ergocalciferol and these are sourced from plants
2. D3 or cholecalciferol – – are naturally occuring and are sourced from animals
3. Calcidiol or 25- hydroxyvitamin D3
– prohormone made in liver
– these are the major circulating form of vit D
4. Calcitriol or 1,25 dihydroxy vitamin d3
– these are the most activated form made in activity
We know that Vitamin D plays a major role in our body system. Like in the bones, it helps in the reabsorption of Calcium and Potassium. Vitamin D also is important in our intestines, in the kidneys and in the Parathyroids.
Most importantly, it is very vital in our immune system. Vitamin D has effects on our innate and adaptive immunity. It increases production of anti inflammatory cytokines and reduces the release of some pro inflammatory cytokines.
Dr Sales further stated that 10.3% of Filipino Children are Vitamin D deficient and that girls are 1.5 x more likely to be deficient than boys. And among the regions in our country, the NCR/ Manila has the highest prevalence of vit D deficiency. The Philippine dietary intake for infants and children is 5 ug/ day or 200 IU / day. The upper limit is 25-50 ug/day { 1000 to 2000 IU/ day).
Dr. Sales explained what “ Shadow Rule” is all about. She said that we generally produce vitamin D when our shadow is shorter than us. When the sun is at a low angle ( like in the early morning or late afternoon), the atmosphere filters out the UVB rays needed for its production. Always remember the best time is between 10 am to 3pm.
Other than the sun, we get vitamin D from
– egg yolk
– mackerel
– cod liver oil
– mushrooms ( 3 oz of which is equivalent to 27 IU of vit D)
– salmon
– beef liver
– canned sardines
– breastmilk ( 22-25 IU/liter of Vit D)
– and Vitamin D supplements
So, this is Vitamin D and its role and functions in our body. Get the sun and eat a well- balanced diet. Be safe and stay protected.