We were discussing hemoglobinopathy — a disorder in which red blood cells can be destroyed — when my brother asked a question.
“Should I take vitamin B6 and iron pills so that my hemoglobin levels could rise, and I won’t look pale?”
Ohers ask the same kind of questions about their health concerns, with some spending hundreds of dollars a month on vitamins of various kinds.
Should we take vitamin supplements daily?
My chemistry teacher, Father Wheeler in Kansas City, would say that the only thing affected by vitamin supplements was your pocketbook. Research shows that vitamin supplements are only needed if a deficiency is confirmed by a laboratory test. In fact, unnecessary vitamin intake might cause harm, especially because fat-soluble vitamins sit in fatty tissues.
So what are vitamins? Vitamins and minerals are chemical substances that are essential for proper function of our cellular metabolism.
Dietary guidelines for Americans (2020-2025) recommend that nutritional requirements for vitamins, minerals and fibers be met through nutrient-rich foods. Vitamins come in both water-soluble and fat-soluble forms.
Fat-soluble vitamins include vitamins A, D, E, and K.
Vitamin A is needed for vision, red blood cell production, immune function and cell differentiation (a process by which a simple zygote changes into complex cells and tissues). Vitamin A is present in food, including orange-colored and dark leafy green vegetables, fish, milk products, eggs, and liver. Vitamin A deficiency can cause night blindness — inability to see in low light — and if severe can make the cornea dry, damaging both the cornea and the retina. Such deficiency is rare in the United States but is a public health concern in poverty-stricken regions of the world.
Vitamin D helps with calcium and phosphorus absorption, promoting bone and teeth formation. Vitamin D can be obtained from fortified milk, eggs, mushrooms and cod liver oil. It can also be synthesized in the skin from a cholesterol derivative, and further modifications in the liver and kidneys produce the active form of this vitamin. Vitamin D and calcium prevent rickets — a disease in which impaired bone development leads to poor growth. Those from 1 to 70 years old need about 15 micrograms or 600 international units daily. For those above 71, the requirement goes up to 20 micrograms.
The Endocrine Society has released guidelines that suggest that vitamin D supplements should only be taken by people in specific risk groups — exclusively breastfed infants, children and adolescents aged 1-18, pregnant women, and adults with pre-diabetes. Taking calcium tablets or vitamin D with calcium can raise blood calcium levels, resulting in calcification of the coronary arteries — they supply the heart — and predisposing user to cardiovascular disease. Current guidelines advise against routine blood tests for vitamin D in healthy individuals. Some studies have suggested a possible role for vitamin D in modulating the immune system, albeit with weak evidence.
Vitamin E exists in different chemical forms, but only alpha-tocopherol is known to meet human needs as the liver takes up and excretes all other forms of vitamin E. Most vitamin E is obtained from nuts, seeds, vegetable oils, green leafy vegetables and fortified cereals. Daily intake from food usually meets the daily requirement of 15 mg for adults and children older than 4. Vitamin E is also known to possess antioxidant properties. People on a low-fat diet are encouraged to eat enough nuts, seeds and leafy vegetables.
Because fat is needed to absorb vitamin E, people with an inability to absorb fat, such as those with Crohn’s disease, cystic fibrosis and problems with secreting bile from the liver into the gut. require water-soluble forms of vitamin E. Individuals with ataxia — lack of muscle control in arms and legs — with vitamin E deficiency have a neurological issue and can damage their nerves and lose the ability to walk unless given supplemental vitamin E.
Vitamin E can counteract the actions of clotting factor that depends on vitamin K and prevent platelet aggregation. That means taking vitamin E in large doses can increase the risk of bleeding.
Found in green leafy vegetables, vegetable oils, and cereal grains, vitamin K helps with blood clotting and wound healing. Actually a family of compounds, vitamin K is needed in microgram quantities per kilogram body weight, and a balanced diet should furnish the daily requirements, any excess being stored in the liver. Lower levels of vitamin K circulate in the blood because, unlike other fat-soluble vitamins, vitamin K is rapidly metabolized by the body. One kind of vitamin K is made in the gut by bacteria in amounts that might partially fulfill the body’s requirements.
In my next column, we will talk about the water-soluble vitamins.
Syed Jamal teachers college-level chemistry, biology and anatomy/physiology and researches phytoremediation and cancer biology. Through its opinion section, Kansas Reflector works to amplify the voices of people who are affected by public policies or excluded from public debate. Find information, including how to submit your own commentary, here.
