We have talked a lot about this vitamin in the past and that is due to the amount of attention it is getting these days! Vitamin D, the “sunshine vitamin,” has been talked about more and more lately! It was once thought to be an understood vitamin without too many surprises, helping with bones and growth but now, there are new findings that D might play a role in preventing or treating Diabetes, heart disease, high blood pressure, multiple sclerosis, cancer and chronic muscular and skeletal pain and many more!! Vitamin D seems to be the new C! The interesting part is, many of us seem to be deficient in this vitamin, even with our main source coming from the sunlight! Are we not getting out enough? It could be because we are not eating enough fortified foods such as milk, some cereals, soy drinks and breakfast bars… That could easily be it when you are trying to watch your diet closely and shying away from several of those fortified foods.
Vitamin D can either be eaten, or made from a “pre-vitamin D” when the sun’s UV rays hit our skin. It then goes through a multi-step process, where it is converted from a less active form to a more active form. Once it is in the most active form, it acts like a hormone and helps the bones to take in more calcium and become stronger, and, also acts on the intestines and causes them to absorb more calcium into the bloodstream.
It very well could be the lack of both UV rays and fortified foods. The process of converting “pre-vitamin D” to the more active form can break down at any of its several stages. It is not as simple as going outdoors into the sun and walaaa you have your Vitamin D for the day! The time of exposure to sun, the angle of the sun, a person’s age, percent body fat and skin pigment all affect absorption of vitamin D and the production from “pre vitamin D” to its active form. Ten to fifteen minutes of direct sunlight exposure, twice weekly, is needed to produce an adequate amount of vitamin D, and, although this seems easy to achieve, it is easier said than done. To get the best exposure to sunlight, it is necessary to be in the sun during the summer season at midday when it is high in the sky. It is also advantageous to live within 25 degrees north or south of the Equator where the sun’s rays are more direct. The less direct the sun’s rays, the less vitamin D we make. There was a study of vitamin D blood levels of people living in Boston (42.2 degrees north of the equator,) showed that during the winter months when the sun is at a more slanted angle, no vitamin D was made. Other studies of other areas more than 25 degrees above or below the equator showed the synthesis of vitamin D to be less during the winter months, and the farther away from the equator, the smaller the amount of vitamin D that was made. hummnn, see all the factors now and still wonder why we may be deficient in this amazing Vitamin?!
Sunscreen and clothing can also block UV light and decrease vitamin D production. Most people either stay fully clothed, to fight the cold or lather up with sunscreen, when it is hot, to avoid the damage from the sun! Darker skin color, higher body fat and age also slow down or block UV light’s effect on vitamin D synthesis. All of these factors can lead to low blood levels of vitamin D and increase our need to get more vitamin D from our diet.
About the only foods which naturally contain vitamin D are some fatty fish and a few varieties of mushrooms. Even with fortified foods, there are legal restrictions on the amount of vitamin D that can be used to fortify foods, so it is hard to get adequate amounts from those foods as well! So if we cannot get enough vitamin D from foods or from sunlight, we must supplement with Vitamin D!
What about how much to take? There is definitely confusion on allotted amounts because the recommended dosage has been found to be not enough! The current recommendations based on the adequate intake (AI) amounts are: 200 IU per day from infancy to 50 years of age, 400 IU per day from age 50 to 70, and 600 IU per day for people over 70 years old. These amounts are not enough, however. It is thought that people with darker skin pigmentation should get 2000 IU per day. Others have suggested that everyone, regardless of age, needs at least 1000 IU per day. I suggest you get 1500 IU’s/day and you can’t go wrong! At one time, there was some concern that too much vitamin D could be toxic, but recent research has shown that 10,000 IU per day can be taken without any toxic effects.
Most multi vitamins do not have enough Vitamin D so I suggest you supplement with pure Vitamin D to ensure you are getting in your daily recommended dose and helping to fight off those unwanted diseases that Vitamin D has been shown to combat.
