The fact that a supplement or drug does not need a prescription from your doctor, it doesn’t mean you can freely take it without risks for intoxication.
All vitamins has a normal acceptable level in blood that we should detect prior to start any supplement.
There is limited evidence to support vitamin supplementation in the prevention of various condition.
On the other hand, we need optimal levels of our vitamins for them to work as cofactors in the processes they intervene.
Please always visit your health care provider prior to start taking a supplement.
Vitamin D
The Recommended dietary allowance (RDA) for vitamin D is 600 IU or 15 mcg daily for adults through age 70 years and for children 1-18 years of age. It increases to 800 IU or 20 mcg in adults older than 71 y/o. This could be changed by your doctor depending on other factors such as sun exposure, latitude, nutrition, chronic diseases, etc.
Exist a tolerable upper intake level for vitamin D as 4000 IU or 100 mcg daily for healthy adults and for children 9-18 years, pregnant and lactating women.
Vitamin D intoxication has been documented in adults taking more than 60,000 IU per day.
Vit D is a fat-soluble vitamin, so it can be deposited in your fat tissue longer time.
Symptoms of acute vit D intoxication includes confusion, polyuria, polydipsia, anorexia, vomiting, muscle weakness, bone demineralization and pain
Vitamin D3 or cholecalciferol is acquired from animal sources like fish, liver, and eggs, while vitamin D2 or ergocalciferol is obtained from plants.
Vit D is involved in calcium and phosphate metabolism to strengthen our bones.
Studies suggest an association between poor vitamin D status and muscle weakness in children and older individuals.
Several studies have evaluated the relationship between vitamin D levels and cancer.
The World Health organization (WHO) identified an association between vitamin D deficiency and risk of colon cancer.
Vit D has major effects on nearly all cells of our immune system.
Vit D deficiency is highly corelated to autoimmune diseases, because of vitamin D’s modulatory effect in the acquire immune system.
Studies have associated vitamin D deficiency and type I diabetes, multiple sclerosis, and inflammatory bowel disease.
Vitamin A
Provitamin A, beta carotene from plants, rarely cause toxicity
Preformed vit A , retinol, retinal, retinoic acid, retinyl esters, from supplements or animal sources (liver) Lab measurements: (fasting) Serum retinol levels < 20 mcg/dL —deficiency. Serum carotene levels are also low.
Vit A prevent xeropthalmia
Intervenes in phototransduction
Vit A is crucial to cellular differentiation and integrity in the eye.
Fat soluble vit has been found to be deficient in patient with Hx of bariatric surgery.
Early symptoms of vitamin A deficiency includes night blindness, Bitot’s spots, poor healing, hyperkeratinization of the skin and lots of taste.
Late symptoms include corneal damage, xerosis, or even blindness.
Vitamin K
Has a major role in coagulation pathways
Involved in bone mineralization
Vitamin K deficiencies in COVID 19 patients were associated with poorer outcomes.
Vitamin K1 is found in green vegetables like spinach and broccoli
Vit K 2 are found in meat, especially liver, cheeses, fermented soybeans, and eggs.
The adequate intake (AI) of vitamin K in adults is 90 micrograms daily in females and 120 mcg daily in
males.
Special considerations has to be kept in mind when supplementing patients on parenteral nutrition, patients on anticoagulant therapy, patients with fat malabsorption.
Some antibiotics and vitamin E supplements may contribute to vitamin K deficiencies.
Vitamin K deficiency causes easy bruisability, mucosal bleeding, splinter hemorrhages, blood in the stools, black stools caused by blood in the stools, blood in urine.
We evaluate vitamin K deficiencies by monitoring PT and INR in patients with bleeding disorders, which presents with prolonged values of PT when is mild and both, PT and INR when is more severe.
Vitamin E
Present in almonds, vegetable oils, cereals.
Alpha-tocopherol is the best-known form of vitamin E.
Vitamin E protect cell membranes from oxidation and destruction.
Known as antioxidant due to its work as a free radicals scavenger.
The recommended daily allowance (RDA) for vitamin E is 15 mg for adults and adolescents, which is equivalent to 22 IU of RRR-alpha-tocopherol and to 33 IU of all racemic alpha tocopherol.
Vitamin E deficiency may cause neuromuscular disorders, hemolysis, pigmented retinopathy.
Low serum levels of vitamin E is defined as below 0.5 mg/dL
