Vitamins: Sources, Functions & More – Fat-Soluble

Deficiencies:

1. Consistent low intake of foods containing fat soluble vitamins.
2. Liver diseases that prevent bile production, so vitamins cannot be absorbed.
3. Diets that are extremely low in fat.

Sources:

• The richest sources of vitamin A are liver and fish oil. Here are some other examples:
  • Carrots
  • Sweet potatoes
  • Milk
  • Bok Choy
  • Apricots
  • Spinach

Functions:

Deficiencies:

Approximately 190 million preschool-aged children are affected by a vitamin A deficiency! A severe deficiency includes permanent blindness and diarrhea. A mild deficiency includes impaired immune system and an increased risk of infection.

Is this true?

Orange skin? Eating too many carrots can make your skin an orange tint! If you consume a lot of fruits and veggies that have bright colors, such as pumpkins or carrots, it may turn your skin yellow due to the build up of beta-carotene in the fat beneath the skin.

Good vision? Beta-carotene, present in bright orange fruit and vegetables, do play a role in good vision.

Supplements? There is always controversy in the research concerning supplements. Some experts suggest that vitamin A supplements should only be consumed by people who suffer from true deficiencies, such as malnutrition or malabsorption.

2. Vitamin D

Sources:

• This vitamin is different from other vitamins as sunlight promotes vitamin D synthesis in the skin. Vitamin D does not need to be consumed from food sources if you expose yourself to sunlight everyday. If you do not, here are some examples of good food sources:
  • Fatty fish
  • Eggs
  • Fortified milk (added vitamin D to milk)

Functions:

• Regulates blood calcium and phosphorus levels
• Increases bone mineralization
• Inhibits tumor proliferation

Deficiencies:

• The most obvious sign of vitamin D deficiency is rickets disease in young children and osteomalacia (adult form of rickets) in adults. Signs of rickets or osteomalacia are softening and weakening of the bones. Children with rickets develop bowed legs. Osteomalacia, most often occurring in women, is due to low intakes of calcium, little sun exposure, or repeated pregnancies and periods of lactation.
  • A supplement of vitamin D is recommended for all breastfed infants.

Is this true?

Sunscreen? Sunscreen does impede vitamin D synthesis. Other factors that may hinder synthesis are air pollution, clothing, and pigmentation of skin. This means you may want to talk to your doctor or dietitian about vitamin D supplements if you always wear sunscreen and clothing outdoors or if you have darker skin.

Greater risk of deficiency? Darker skin individuals need longer exposure to sun to promote vitamin D synthesis, which makes them more at risk of deficiency. Babies are also more at risk as breast milk is not fortified with vitamin D, and babies are rarely exposed to sunlight (or if so, with sunscreen).

3. Vitamin E

Sources:

• Blueberries
• Vegetable oils
• Sunflower seeds

Functions:

• Antioxidant
• Blocks Free Radicals:
  • Free radicals are unstable atoms that can harm cells due to chain reactions, causing illness. Antioxidants block the activity of free radicals and protect cell structure. Environmental factors, such as cigarette smoke or polluted air can increase your free radical count.

Deficiencies:

Vitamin E deficiencies are rare as it is so widespread in different types of foods. The most common vitamin E deficiency occurs in premature babies who are born before the transfer of vitamin E from the mother. Insufficient vitamin E cause the infant to become anemic. The few cases of vitamin E deficiencies in adults include symptoms such as loss of muscle coordination and reflexes, in addition to impaired movement, vision, and speech.

Is this true?

Frying? Heat processing destroys vitamin E. Additionally, most processed, deep-fried, fast foods retain little vitamin E due to oxidation.

4. Vitamin K

Sources:

• K1: dark green leafy greens
• K2: Produced by intestinal bacteria

Functions:

• Necessary for blood to clot
• Necessary for synthesis of bone proteins that bind minerals. Vitamin K consumption reduces risk of hip fracture… Eat your leafy greens!

Have you ever wondered how you stop bleeding after getting a cut ?Without vitamin K, blood could not clot, which would cause excessive bleeding. We are protected by the fact that our bodies produce vitamin K, unlike vitamin D.

Deficiencies:

Vitamin K deficiencies are also rare. Even if leafy greens are rarely consumed, vitamin K is produced endogenously by the gut bacteria (K2). However, deficiencies could occur in newborn infants. The vitamin-K producing bacteria is not yet produced in newborns. It takes a few weeks to be produced. For this reason, newborns are given a single dose at birth. Finally, low bile production and fat malabsorption can lead to deficiencies. Symptoms include hemorrhage, and poor skeletal mineralization.

Is this true?

Blood thinners? The accumulation of plaques within arteries cause some individuals to take blood thinners. This type of medication counteracts the actions of vitamin K. Therefore, it is important to continue eating leafy greens, a food source of vitamin K, if prescribed blood thinners.

Antibiotics? Some antibiotics destroy the gut bacteria (K2), but with time it regenerates.

Conclusion: Eat a variety of colours, shapes, and flavours !

Unless you suffer from a specific disease, you are pregnant, lactating, or are feeding an infant, eating a variety of fruits, vegetables, proteins, and fats will allow you to reach your recommended daily intake of fat soluble vitamins. Our body craves a diversity of foods for a reason! Be aware of consuming too much of a fat soluble vitamin as the body can store it and reach toxic levels. Severe negative health outcomes can occur if you reach toxic level of a fat soluble vitamin.

References