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What you need to know about Vitamin D (part 2)
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Currently, the desired levels are 30 to 75 ng/mL-nmol/L, and anything less is seen as deficient, though higher doesn’t necessary mean you’re at a toxic level. The concern is for consistent levels above the 200 range.
The bottom-out number should really be 30; however, we’re seeing study after study show that levels are constantly hitting below this all around the world, and the aftereffect is becoming an epidemic.
| ng/mL | nmol/L | Status |
| < 11 | < 27.5 | These levels suggest severe illness, usually seen in rickets or sick infants. |
| < 10-15 | < 25-37.5 | While not directly or instantly crippling, these levels overtime may contribute to illness both acute and chronic. |
| ≥ 30 | ≥ 75 | Seen by some to be the desired range and achieving of optimal health. |
| Consistently > 200 | Consistently > 500 | Could be toxic and lead to hypercalcemia and hyperphosphatemia. |
Serum 25-hydroxyvitamin D [25(OH)D] concentrations and health
How Do You Get It?
Vitamin D is the “sun vitamin,” meaning that you should receive 80 to 100% of your intake from the sun. When ultraviolet (UV) rays hit the skin, they’re absorbed and converted, setting into motion your body’s process of creating vitamin D. In truth, this should be the end all for receiving your daily intake.
However, things just aren’t that simple.
What About Food Intake?
Vitamin D can be found in small amounts in certain fishes, fortified milks, and egg yolks.
The problem is that the intake would have to consist of very high levels and multiple times daily to give you the effects you need. It also would depend on the quality of your food. With fish, for instance, it’s been shown that farmed salmon (fish raised in tiny boxes eating crappy fish food) held at least 25% less vitamin D than wild-caught salmon.(1)
Take-home point being, if you think that the Wal-Mart fish nutrients are doing something for you, think again. What they eat is what you eat. As well, the fortified milk and cereal claims of vitamin D can be off by as much as 80% of what the label says.
Here’s a chart that gives you a general rundown of food sources for vitamin D:
| Food | IU per serving | Percent DV |
| Cod liver oil, 1 tablespoon | 1,360 | 340 |
| Salmon, cooked, 3.5 ounces | 360 | 90 |
| Mackerel, cooked, 3.5 ounces | 345 | 90 |
| Tuna fish, canned in oil, 3 ounces | 200 | 50 |
| Sardines, canned in oil, drained, 1.75 ounces | 250 | 70 |
| Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup | 98 | 25 |
| Margarine, fortified, 1 tablespoon | 60 | 15 |
| Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) | 40 | 10 |
| Egg, 1 whole (vitamin D is found in yolk) | 20 | 6 |
| Liver, beef, cooked, 3.5 ounces | 15 | 4 |
| Cheese, Swiss, 1 ounce | 12 | 4 |
Selected food sources of vitamin D (2,3)
Differences in Vitamin D
Vitamin D comes in two main forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). There’s a D1, D3, and D5, but in short, their importance and our control of them isn’t the main topic here.
Vitamin D2 is made by the UV irradiation of ergosterol in yeast, and vitamin D3 is made by the irradiation of 7-dehydrocholesterol from lanolin and the chemical conversion of cholesterol.
It’s suggested that D3 is far superior to D2 at raising levels in the body and holding them higher for extended periods of time.(4,5) Because of this, if you’re going the supplement route for your intake of vitamin D, D3 is the winner of the group.
The overall goal of vitamin D is to raise serum levels in the body and do so as best as possible. To date, both D2 and D3 supplements at prescription-grade levels have shown to do this. D2, however, has been shown to be toxic at higher levels. (It should be noted that you can’t achieve toxic levels of D in the body with just the sun.)
(...Final part tomorrow)
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