There is increasing evidence that most North American adults have significant Vitamin D deficiency due to avoidance of sunlight and aging of the enzyme system that creates Vitamin D in the skin. I frequently measure vitamin D levels in my adult patients and confirm severe deficiencies, even in patients taking the current government recommended 400 units daily of Vitamin D.
The official amount of sun exposure needed to create adequate Vitamin D is 20 minutes at high noon to 80% of the body. Personally I tried that for two days in a row at summer solstice sitting in a bathing suit on a boat. I was tanned and not using sunscreen. I did swim frequently all day. My Monday morning vitamin D3 level was subnormal. The explanation - I sweated and washed off the Vitamin D before it be could be absorbed back into my body.
Dr. Michael Holick, one of the lead researchers for Vitamin D in this country, and author of the original recommended RDA of 400 units daily, has publicly advised all adults to take 2000 units daily.
So what Vitamin D is best? There are two forms of Vitamin D on the market. Vitamin D2 or ergocalciferol, is not as potent as Vitamin D3 and I would not recommend taking it. The research about Vitamin D has been done using Vitamin D3 or cholecalciferol and this is the one to take.
Vitamin D3 is fat soluble and should be taken with food. Once daily dosing is enough. I do recommend having a blood test for Vitamin D3 level before starting doses above 1000 units per day.
Vitamin D excess can cause elevations in blood calcium levels but many researchers now think that it would require daily dosing of 10,000 units of D3 to produce this in most people.
For all its many benefits, vitamin D remains one of the least expensive supplements on the market. A 4 month supply of 2000 units daily dosing of D3 can cost below $15.
drBob
There is increasing evidence that most North American adults have significant Vitamin D deficiency due to avoidance of sunlight and aging of the enzyme system that creates Vitamin D in the skin. I frequently measure vitamin D levels in my adult patients and confirm severe deficiencies, even in patients taking the current government recommended 400 units daily of Vitamin D.
The official amount of sun exposure needed to create adequate Vitamin D is 20 minutes at high noon to 80% of the body. Personally I tried that for two days in a row at summer solstice sitting in a bathing suit on a boat. I was tanned and not using sunscreen. I did swim frequently all day. My Monday morning vitamin D3 level was subnormal. The explanation - I sweated and washed off the Vitamin D before it be could be absorbed back into my body.
Dr. Michael Holick, one of the lead researchers for Vitamin D in this country, and author of the original recommended RDA of 400 units daily, has publicly advised all adults to take 2000 units daily.
So what Vitamin D is best? There are two forms of Vitamin D on the market. Vitamin D2 or ergocalciferol, is not as potent as Vitamin D3 and I would not recommend taking it. The research about Vitamin D has been done using Vitamin D3 or cholecalciferol and this is the one to take.
Vitamin D3 is fat soluble and should be taken with food. Once daily dosing is enough. I do recommend having a blood test for Vitamin D3 level before starting doses above 1000 units per day.
Vitamin D excess can cause elevations in blood calcium levels but many researchers now think that it would require daily dosing of 10,000 units of D3 to produce this in most people.
For all its many benefits, vitamin D remains one of the least expensive supplements on the market. A 4 month supply of 2000 units daily dosing of D3 can cost below $15.
drBob