Vitamin D3 (cholecalciferol) is now known to contribute to normal:
- absorption/utilisation of calcium and phosphorus
- blood calcium levels
- bone maintenance
- normal muscle function maintenance
- Vitamin D contributes to the maintenance of normal teeth
- Vitamin D contributes to the normal function of the immune system
- Vitamin D has a role in the process of cell division
- Calcium and vitamin D are needed for normal growth and development of bone in children
- Vitamin D is needed for normal growth and development of bone in children.
Principally manufactured by sunlight, Vitamin D3 deficiency has reached pandemic proportions due to our indoor lifestyles. It is suggested in the medical literature that the current recommended daily intake is insufficient.
Vitamin D Scientific Studies
Vitamin D is currently being studied for its roll in many of our most serious and challenging illnesses. For information about the most recent scientific studies please visit http://www.grassrootshealth.org
Vitamin D from the Sun
Sunlight is the best source of vitamin D, as it will never lead to vitamin D toxicity. One should expose as much skin as possible to the sun, without risking sunburn. Sunscreens however will stop you from producing vitamin D. 95% of vitamin D production is eliminated with a cream of sun proof factor (SPF) 8. It is also important to know that it takes about half an hour for the vitamin to be absorbed into the blood stream. So do not shower for at least 30 minutes after sun exposure.
For maximum benefit, only expose yourself to the sun long enough to turn the skin the palest shade of pink. There is no additional benefit after this point, and you will only be contributing to oxidative stress and skin aging.
Who Needs Vitamin D Supplementation?
It is estimated that 80% of people in Northern Europe and America are vitamin D deficient. The low angle of the sun, combined with the amount of time now spent inside, make it almost impossible for people to produce sufficient of this vitamin with its vital, hormone-like properties. Because there are relatively few foods that contain vitamin D to support us, especially through winter, it may be wise to rely on a vitamin supplement to meet your daily needs.
Vitamin D reserves are stored principally in the liver, where they halve, roughly every two months, even without use. It is therefore now postulated that colds and flu, together with SAD (seasonal affective disorder) strike during the winter months simply because these reserves have depleted and our immunity, brain and nervous functions begin to suffer.
Vitamin D Supplementation Dosage
Currently Vitamin D blood concentrations of 50 to 60 millimoles per liter are thought to be optimum, although there is discussion as to whether this should be revised to 80 - 100 millimoles. Toxicity is only thought to be reached at levels well over 200 mm/l.
According to the Journal of Nutrition March 2009; 139(3):540-6 supplementation dosages during the autumn and winter months are:
|Vitamin D Dose Recommendations|
|Below 5||35 units per pound per day|
|Age 5 - 10||2500 units|
|Age 18 - 30||5000 units|
|Pregnant Women||5000 units|
There is no way to know if the above recommendations are correct. The ONLY way to know is to test your blood. Ideally your blood level of 25 OH D should be 60ng/ml. Too much vitamin D may cause nausea, weakness, constipation, irregular heartbeat, weight loss, seizures, and irritability.
Doses of 1,800 iu units a day can cause stunted growth in infants and young children. Too much vitamin D may lead to serious health conditions. It is highly recommended that you monitor your blood vitamin D levels.