What are they?
Fat-soluble vitamins are those that dissolve in fats (vitamins A, D, E and K). Only vitamin D can be synthesized by our body with exposure to sunlight, while the others must be introduced with food.
Food sources
Vitamin A is mainly found in green leafy vegetables (along with C and K), but also in milk and dairy products.
Vitamin A can also be taken in the form of beta-carotene, a precursor that is then transformed by the liver into the active form. Yellow-orange or dark green fruits and vegetables such as: carrots, pumpkin, broccoli, spinach, apricots, melon and papaya are rich in beta-carotene.
Cod liver oil, eggs and fish are rich in vitamin D.
Adequate amounts of vitamin E are present in: olive oil and vegetable oils in general, wheat germ, whole grains, green leafy vegetables and nuts.
Vitamin | Food sources |
---|---|
Vitamin A | Green leafy vegetables
Milk and dairy products Yellow-orange or dark green fruits and vegetables |
Vitamin D | Cod liver oil
Eggs Fish |
Vitamin E | Olive oil and vegetable oils in general
Wheat germ Grains Green leafy vegetables Nuts |
Absorption
Medications (laxatives, oral contraceptives, aspirin, antibiotics), coffee, smoking, and alcohol can reduce the body’s absorption or utilization of vitamins.
The reduced availability may also be due to a disorder of malabsorption in the gastric and intestinal (subjects who have undergone surgery or who suffer from chronic and inflammatory bowel diseases).
Effects
Fat-soluble vitamins strengthen the nervous structures (vitamins D and E), fight infections and are above all known for their antioxidant power.
In particular, vitamin D has the function of stimulating the intestinal absorption of calcium and phosphorus , promoting the mineralization of the bone matrix.
Furthermore, they ensure the correct development of bones (vitamin D) and reduce the risk of osteoporosis ; they are important for the production of red blood cells and visual pigments (vitamin A) and regulate blood Clotting ( vitamin K ).
Shortage
Vitamin D deficiency is evident with a decreased concentration in the serum of calcium and phosphorus, in severe forms it can lead to rickets, muscle weakness and bone deformations.
Integration
Generally a varied and balanced diet can cover the entire requirement of fat-soluble vitamins. However, in conditions of increased need, such as growth, pregnancy, intense sporting activity, ageing, menopause , it may be useful to supplement them.
Recommended doses
The recommended daily doses are as follows: A 800 μg (5 mg if in the form of beta-carotene); D 5 μg; And 10mg.
Precautions
Unlike water-soluble vitamins , excess fat-soluble vitamins tend to accumulate in the liver and tissues. It is therefore important to resort to their supplementation, using quantities in line with the recommended daily dosage (RDA).
Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.
The blog covers a wide range of topics related to health and wellness, with articles organized into several categories.