Vitamin A
Vitamin A used by the body in the form of retinol has a wide range of functions.
This antioxidant helps prevent night blindness, promotes fetal growth and development, maintains healthy skin and mucous membranes and
is required for the functioning of a healthy immune system.
Studies have shown that infectious diseases are of a higher incidence in countries
where there is a higher rate of vitamin A deficiency.
Food sources contain vitamin A compounds that are converted by the body to retinol.
Cod liver oil, liver, sweet potatoes, and spinach are among the many sources.
Since vitamin A is fat soluble and is stored by the liver, toxicity is a possibility usually in cases of consuming
high doses of Vitamin A supplements.
Consider UL (Upper Limits) in cases of fish
oil, organ meats and supplement intakes, not vegetable sources.
The Vitamin A values are calculated using the USDA Vitamin A Retinol Activity Equivalents.
DV - 5000.IU - UL
RDA - Children 4-8 years - 1333.IU - UL Upper Limits - 3,000.IU
RDA - Women 31-50 years - 2333.IU - UL Upper Limits - 10,000.IU
RDA - Lactating 31-50 years - 4333.IU - UL Upper Limits - 10,000.IU
RDA - Men 31-50 years - 3000.IU - UL Upper Limits - 10,000.IU
Vitamin C
Vitamin C (ascorbic acid) is an important
antioxidant
needed by the body to produce collagen,
the structural component in blood vessels, ligaments, tendons and bones.
Vitamin C also acts as a detoxifier and enhances the absorption of iron.
Since vitamin C is water soluble, it cannot be stored in the body and as the human
body cannot make vitamin C, we must consumed it everyday.
Food sources include strawberries, citrus fruits, sweet peppers and spinach.
Cooking heat destroys vitamin C.
DV - 60mg
RDA - Women 31-50 years - 75mg - UL Upper Limits - 2,000mg
RDA - Men 31-50 years - 90mg - UL Upper Limits - 2,000mg
Vitamin D
Vitamin D is needed for the proper absorption of calcium, the important mineral needed to promote a strong skeletal system.
Vitamin D also plays an important role in regulating certain cell activities and in that role Vitamin D may help reduce the risk of some types of cancers.
The body can synthesize active vitamin D through the skin upon exposure to sunlight, 5-15 minutes on sunscreen-free light skin three times per week between 11 am and 2 pm, spring, summer and fall.
Dark skinned people synthesize significantly less vitamin D through the skin.
Other sources of vitamin D include cod liver oil, fatty-fleshed fish such as salmon and sardines and vitamin D enriched milk products.
DV - 400.IU
RDA - Women 31-70 years - 600.IU - UL Upper Limits - 4,000.IU
RDA - Women 70+ years - 800.IU - UL Upper Limits - 4,000.IU
RDA - Men 31-70 years - 600.IU - UL Upper Limits - 4,000.IU
RDA - Men 70+ years - 800.IU - UL Upper Limits - 4,000.IU
Vitamin E
Vitamin E (alpha-tocopherol) plays a major role as an
antioxidant (preventing
oxygen in the body from combining with waste to form toxic substances (free
radicals) that cause damage). In that role, vitamin E protects bodily cell
membranes and in turn helps protect the immune system, reduces risk of heart
disease and cancers. Food sources include almonds, peanuts, avocados, vegetable
oils and green leafy vegetables.
The UL(Upper Limits) values for Vitamin E may apply to intake obtained from supplements, fortified foods, or a combination of the two.
DV - 30.IU
or 20mg
RDA - Women 31-50 years - 15mg - UL Upper Limits - 1,000mg
RDA - Men 31-50 years - 15mg - UL Upper Limits - 1,000mg
Vitamin K
Vitamin K is a fat soluble vitamin that has an essential role in helping to maintain normal blood clotting function.
Food sources include green leafy vegetables, broccoli and vegetable oils.
DV - 80mcg
RDA - Women 31-50 years - 90mcg - UL Upper Limits - ~
RDA - Men 31-50 years - 120mcg - UL Upper Limits - ~
Beta-carotene
Beta-carotene is a carotenoid, a compound of Vitamin A of which the body can convert into the usable vitamin A retinol. As a powerful
antioxidant,
studies have shown that diets rich in beta-carotene can inhibit the growth
of many types of cancers but consumption should come from fruit and vegetable food sources rather than from supplements.
With some conditions, supplements of beta-carotene may have an adverse effect on cancer risk. More research is needed.
Our bodies convert beta-carotene into active vitamin A retinol at a ratio of 12 to 1. But to get the optimal benefit of
beta-carotene's antioxidant properties, try to meet your vitamin A requirements through
beta-carotene rich plant sources, rather than retinol from animal sources.
The table below shows The Vitamin A Required vs Beta-carotene intake equivalent from plant sources.
| Type |
Group |
Vitamin A (IU) |
Beta-carotene(mcg) |
| DV |
|
5000 IU
|
18,000 mcg |
| RDA |
Children 4-8 years
|
1333 IU
|
4,800 mcg |
|
RDA |
Women 31-50 years
|
2333 IU
|
8,400 mcg |
|
RDA |
Breast Feeding 31-50 years |
4333 IU
|
15,600 mcg |
|
RDA |
Men 31-50 years |
3000 IU
|
10,800 mcg |
Rich food sources are deep orange fruits and vegetables such as carrots, sweet potatoes and pumpkin and greens such as spinach, kale and collards.
Since beta-carotene is fat soluble, food sources should be consumed with some fat or oil for better absorption by the body.
DV - No recommendations have been set.
RDA - No recommendations have been set.
Lycophene
Lycopene is a carotenoid in the Vitamin A family but our bodies do not convert it into vitamin A.
However, recent studies have lead many in the medical community to believe it may be a more powerful
antioxidant than beta-carotene.
Research have shown those that consumed 10mg (10,000mcg) or more
daily of lycopene benefited from significant reductions of risk in developing heart disease,
macular degeneration and cancers such as prostate in men.
Cooked and processed tomato products seem to be among the best sources of lycopene because the cooking process breaks down the plant cell walls making lycopene easier
to absorb. Watermelon and pink grapefruit are also good sources.
DV - No recommendations have been set.
RDA - No recommendations have been set.
Lutein and Zeaxanthin
Lutein and Zeaxanthin are vitamin A compounds called carotenoids, but are not converted to vitamin A in our bodies.
As antioxidants,
they will offer health benefits such as promotion of healthy immune systems, skin, heart, veins and arteries. Lutein and zeaxanthin are found in the human lens.
Research as shown a strong correlation between regular intake of lutein and zeaxanthin and
reduced risk of developing macular degeneration and cataracts. Consuming at least 6mg (6000mcg) daily of foods rich in lutein and zeaxanthin showed the most benefit.
The effect of intake by way of supplements needs further research.
Since most analytical systems do not separate lutein and zeaxanthin, USDA combines both as one value.
Food sources include green leafy vegetables such as collards, spinach, kale and broccoli.
DV - No recommendations have been set.
RDA - No recommendations have been set.