Vegan 101: Can you get enough vitamin D without milk?

[Guest guest]

Vitamin D is a little bit of an imposter; it's not really a vitamin at all

because, technically, it's not required in the diet. We can make all we need

with adequate skin exposure to sunlight.

 

Theoretically, it doesn't take much effort to synthesize enough vitamin D. Just

20 to 30 minutes in the sun three times a week can do it for some people. But

older people and those with darker skin make vitamin D less efficiently. Smog

interferes with vitamin D manufacture as well. So does the use of sunscreen.

 

It's become clear that most people need an additional source of vitamin D to

avoid deficiency. Vitamin D is needed for healthy bones, but it also may play a

role in reducing cancer risk and depression.

 

Vitamin D in foods

 

The need for a dietary vitamin D source became clear in the industrial age when

jobs took many people, including children, out of the sunlight and into the

factory. With few natural dietary sources of this vitamin—it's generally found

only in fatty fish and some eggs—deficiency became widespread. The government

responded by requiring vitamin D fortification of milk.

 

Unless it's added to it, though, milk does not contain vitamin D. And because it

is added to large volumes of milk, there has been evidence of quality control

problems, with vitamin D not being well mixed in the milk. A series of studies

from the 1990s showed that, in some factories, the vitamin D was poorly

distributed. Some cartons of milk ended up with no detectable vitamin D while

others had extremely high amounts. This raised questions among experts about

whether people could depend on milk for meeting vitamin D requirements.

 

Vegan vitamin D

 

Most of the vitamin D used to fortify foods is vitamin D3 or cholecalciferol.

It's derived from animals—often from the wool of sheep. An alternative source is

vitamin D2, or ergocalciferol, which comes from bacteria. Among vitamin D

experts, there has been debate about D2 and whether it works as well as D3. But

recent research shows that the vegan vitamin D is just as effective as the type

derived from animals.

 

Most mainstream products—like breakfast cereals—contain vitamin D3. But a

growing number of vegetarian foods, including soy and other nondairy milks, are

fortified with D2. There are also D2 supplements in nongel caps available now.

 

The recommended intake (referred to as an Adequate Intake or AI) for vitamin D

is 5 micrograms per day for adults, 10 micrograms for those over age 50 and 15

micrograms for people over the age of 70. But there is evidence that these

amounts are much too low. In fact, recent research suggests that low vitamin D

status is extremely common among all population groups. The growing consensus is

that recommendations for vitamin D intake need to be raised.

 

If you get regular mid-day sun exposure without sunscreen on days when the sun

is hot and bright enough to cause sunburn, you are probably making enough

vitamin D. But this may not be true for those with more skin pigmentation or for

older people. It's probably prudent for everyone to get 25 micrograms of vitamin

D daily, particularly during times of the year when there is no hot sunlight or

if you avoid the sun. Vegans can choose supplements of vitamin D2.