How much vitamin D should I be taking daily?

Vitamin D is absolutely critical to health and most Americans are deficient if they don’t take a supplement. Technically, it is a fat-soluble vitamin that the body converts into a hormone and every cell in the body appears to have vitamin D receptors. For millennia, Vitamin D was produced in the skin with exposure to sunlight, but only a rare person today receives enough sunlight on their skin today to produce enough vitamin D to meet their needs. There are two forms of Vitamin D that come in supplement form, Vitamin D2 and D3, with D2 having 20% of the activity of D3. The discussion below refers to the Vitamin D3 form.

Vitamin D deficiency is associated with:

  • Osteoporosis fractures, loss in bone density, and bone pain
  • Increase risk for cancer (especially breast, prostate, colon, and pancreas).
  • Increased risk for autoimmune disease, (especially multiple sclerosis).
  • Increased risk for cognitive decline, Alzheimer’s, and depression
  • Elevated blood pressure and increased risk for heart attacks, strokes, and other forms of cardiovascular disease.
  • Increased risk for diabetes.

Unfortunately, unless people take a supplement with Vitamin D, most people in American today have low vitamin D levels and are at elevated risk for these major problems.

How Much Vitamin D Do You Need?

Optimal intake varies from 1,000 to 2,000 IU of vitamin D3 daily. If your level is very low, then often taking 5,000 IU daily for 2 months will bring you back to normal, then consider 1,000 to 2,000 IU daily long term. Some people may need to take 3,000 IU daily to maintain a normal level. If your require more than this, please check with your medical provider as this could be a sign of the following:

  1. You don’t convert 25-OH vitamin D to 1, 25 di-hydroxy vitamin D properly, which can cause immune suppression if missed.
  2. Gastrointestinal absorption which can cause many other health issues that needs to be addressed.
  3. Decreased genetic activity to transport vitamin D, which means you simply need to take more vitamin D to meet your needs.

Can you get 1000 to 2000 IU of vitamin D from the sun? Likely not. Keep these facts in mind:

  • Ultraviolet UVB radiation with of 290–320 wavelength (311 peak) nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to 25-hydroxy-vitamin D3, which in turn becomes 1, 25-dihydroxy-vitamin D3.

A 20 y/o, naked, at noon with Florida summer exposure producing erythema (sun burn) makes 10,000-20,000 IU per hour; this would be plenty

A 20 y/o wearing shorts and a sleeveless shirt at 10 am, Florida year round, for 30 minutes with no sunscreen 3 x / week makes 200-400 IU / day

– Sun screen use (>8 SPF) blocks nearly all vitamin D formation

– If you are north of the Atlanta-San Francisco latitude, sunlight is only effective 6 months/yr to produce vitamin D (not enough UVB)

– 50 y/o skin makes 50% and 70 y/o skin makes 25% of vit D as 20 y/o skin

– Only 50% vitamin D production occurs when it is cloudy

– Nearly no vitamin D production through glass

What are food sources for Vitamin D3? Add them up and see if your sunshine exposure plus food allow you to reach 1000 to 2000 IU daily.

  • Cold water fish 3.5 oz: 100-350 IU per serving (fattier fish has more vitamin D)
  • Milk (Ca-fortified OJ, Ca-fortified soy milk): 100-150 IU per 8 ounces
  • 1 Egg Yolk: 25 IU
  • Cheese, 1 ounce: 5-10 IU

Can I get my Vitamin D from a supplement? Absolutely, and if you don’t get at least 1,200 to 2,000 IU of vitamin D from food or sunshine, then clearly you should take a vitamin D supplement. Here are Vitamin D sources that I provide through our Ten Years Younger supplement line. Add your sun exposure, food intake, and supplement intake all together, and if you are in the 1,200 to 2,000 IU range daily, great!

  • Ten Years Younger (TYY) Essential Nutrients for Bone Support (1 pack taken twice daily provides 1100 IU vitamin D3)
  • Ten Years Younger (TYY) multivitamin with either the joint support or the arthritis support pack (1 pack taken once daily provides 1,650 IU vitamin D3)
  • TYY Multivitamin (500 IU vitamin D3 in 2 capsules)
  • TYY Fish oil with extra vitamin D and vitamin K (1000 IU vitamin D3)
  • OsteoForce (bone support tablets) with 150 IU of vitamin D3 per tablet, plus calcium, magnesium, and vitamin K
  • Vitamin D synergy (DFH) with 2,000 IU vitamin D3 and 200 mcg of vitamin K.
  • Vitamin D supreme (DFH) with 5,000 IU vitamin D3 and 550 mcg of vitamin K.
  • Vitamin D drops (Emulsi-D3, DFH) 2000 IU of vitamin D3 per drop

Should you measure your vitamin D level?

Clearly if you have specific medical issues that are related to vitamin D deficiency, then at least once check your vitamin D 25-OH level. If money is an issue, then first take at least 1,000 to 2,000 IU daily for 2-3 months, then check your level. These medical problems would include: rickets, osteoporosis, multiple sclerosis, any form of an auto-immune disorder, or any high risk factors for cancer.

At the Masley Optimal Health Center we check all our patient’s Vitamin D levels at least once to ensure they are normal.

A normal level would be >32 with less than 30 clearly deficient. An optimal level is controversial amongst scientists, but I recommend 40-70 ng/ml. What level is toxic with long term use isn’t known, although most discourage taking supplements to raise levels above 100 ng/ml.

For patients who need more than 3,000 IU daily to achieve normal vitamin D levels, at least once I’ll also check a 1,25 di-OH vitamin D level, plus check for fat soluble vitamin malabsorption.


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