What is Vitamin D?
Vitamin D is well-known to be necessary for the
absorption of calcium in the intestines, but we are learning that
it also has many other vitally important functions in the body,
including for healthy immunity.
The human body can manufacture plentiful amounts of Vit D if
exposed to sunlight during the summer. There are small
amounts of vitamin D in a few foods, but it’s very hard to obtain
sufficient amounts from the diet alone.
Importance of Vitamin D
A key activity of vitamin D is to facilitate the absorption
of calcium, vital to build and maintain strong bones. Children
with severe Vitality D deficiency can develop rickets, where the
long leg bones become deformed due to lack of calcium. In
recent years researchers have found that Vitamin D also has
numerous other crucial functions throughout the body, including
supporting joints and muscles, promoting healthy mood, and
combatting a variety of chronic diseases.
Vitamin D3 deficiency is very commonly seen in obesity, diabetes, hypertension,
depression, fibromyalgia, chronic fatigue syndrome,
autoimmune conditions, osteoporosis and Alzheimer’s disease.
But specially important for us all during the current pandemic is
to understand that vitamin D is essential for maintaining a
robust immune response.
Study published in recent weeks show that Covid patients with adequate blood levels of Vit D are much less likely to suffer severe reactions to the virus, or to die,
compared with those with low levels.
Surveys repeatedly show that many people in N America and
Europe have Vit D levels too low for optimum health, especially
during the winter months.The only foods containing (small)
amounts of Vit D include egg yolk, beef liver and fatty fish.
Some convenience products (e.g. breakfast cereals) are
fortified with small amounts of the D2 form of Vit D, which is
less potent than the D3 found in supplements.
However, obtaining adequate amounts is best ensured by
regularly exposing the skin to sunlight through the warmer
months. In the Uk and Ireland it is recommended to supplement
Vit D, at least between the months of November and March, to
compensate for weak sunlight intensity during this time.
Can you take too much Vitamin D?
Vitamin D toxicity, although very rare, could occur from
taking excessive amounts of vitamin D. This cannot happen
from sun exposure or dietary sources, but could potentially
occur from megadosing vitamin D supplements over months.
The Recommended Dietary Allowance (RDA) for adults is 600
IU of vitamin D a day.
However, many scientists specialising in Vit D research recommend significant higher doses to both achieve and maintain adequate blood levels during the summer.
It is generally regarded as safe for most adults to take up to
4000 IU/day during the winter (less for children, based on size).
Those with darker skins living in colder climates are recognised
to need higher doses than lighter-skinned people. This is likely
part of the reason that Covid-19 is proving more lethal for black
people than whites - at least beyond the tropics.
Vitamin d is vital off our health in many ways. There is
widespread deficiency across temperate regions of the world,
and this is known to be factor in diseases such as obesity,
diabetes, as well as reduced resistance to coronavirus. I would
highly recommend getting a good suntan this summer, followed
by taking a vitamin D supplement during the coming winter