Essential Vitamins: Not Enough, Just Right, or Too Much?

Helping our kiddos grow up healthy is a top priority for mommas, and providing proper nutrition is key. How can we ensure that our children are getting enough of the essential vitamins that they need? What are the risks associated with too few (or too many) vitamins? Should we give our tots multivitamins to help cover any unintentional nutritional gaps? Short answer: most children obtain the vitamins they need from diet, but read on for everything you never knew you wanted to know about vitamins!

Vitamins are organic compounds that our bodies can't make but need for survival. Exclusively breastfed infants rely on momma's diet to provide these vital vitamins. The table above frames daily recommendations by age for the most clinically relevant vitamins as judged by risks of deficiency and potential for toxicity (Diab and Krebs, 2018). In a national random sample of 3,022 infants and toddlers, researchers found that "generally, healthy infants and toddlers can achieve recommended levels of vitamin intake from food alone. Caregivers [should be encouraged] to use foods rather than supplements" (Briefel et al., 2006). Of note, Vitamin E deficiency (more prevalent in supplement nonusers) and Vitamin A excess (more prevalent in supplement users) was reported. Each vitamin's biological role, as well as the risks associated with not enough or too much, are laid out below based on Diab and Krebs, 2018.

Vitamin A is important for vision, immunity, cell differentiation, and growth. Vitamin A comes in two flavors: proform (retinol = ready-to-use vitamin A, found in animal sources and skincare products) and preform (beta-carotene = must be converted to vitamin A, found in vegetables). Vitamin A deficiency can cause a range of issues from vision problems to death. A large carrot provides 600 mcg of vitamin A in the form of beta-carotene, so it's easy to achieve proper intake through food alone. On the flip side, proform vitamin A toxicity (single dose of ≥150,000 mcg for adults, less for children) can cause increased intracranial pressure leading to headache, blurred vision, vertigo, and a bulging soft-spot in infants. Too much vitamin A can also disrupt fetal development, which is why pregnant mothers should be especially vigilant about retinol excess.

Vitamin B12 supports nervous system function and is needed for red blood cell formation and DNA synthesis. Vitamin B12 is naturally found in animal products, with one egg providing 0.4 mcg and a 6 oz steak providing 13 mcg. People on long-term vegetarian and vegan diets should therefore consider incorporating B12-fortified foods. Vitamin B12 deficiency symptoms in children include growth faltering, developmental regression, tremors, low muscle tone, lethargy, irritability, and feeding difficulties. There's little danger of vitamin B12 toxicity.

Vitamin C is an antioxidant that is vital for healing and necessary to form blood vessels, cartilage, muscle, and collagen in bones. One large orange contains 100 mg of vitamin C, which is why citrus fruits are recommended to prevent vitamin C deficiency (aka scurvy). The earliest symptoms of vitamin C deficiency in children are fatigue and refusal to walk, followed by bone abnormalities, bleeding, and anemia. Excess vitamin C is not regarded as harmful.

Vitamin D helps your body absorb calcium, which is necessary to build and maintain healthy bones. One cup of vitamin D-fortified milk contains 100 IU, and vitamin D can be produced in the skin during exposure to sunlight. However, vitamin D deficiency is widespread around the world with symptoms including restlessness, lack of sleep, slow growth, motor development delay, and softening of bones (aka rickets). Breastfed babies are especially at risk for vitamin D deficiency, and breastfeeding mothers are encouraged to supplement with 6,000 IU/d to produce milk with 400 IU/L or provide baby with vitamin D drops. Vitamin D toxicity via supplements (≥60,000 IU/d) can cause a buildup of calcium in your blood (hypercalcemia) leading to nausea and vomiting, weakness, frequent urination, and calcium stones.

Vitamin E is an antioxidant important for the health of your blood, brain, skin, vision, and reproductive system. Vitamin E is found in an abundance of natural sources, with 20 almonds providing 7 mg. Despite this, studies have suggested that the vitamin E intake of a large percentage of children is below the recommended amount (Briefel et al., 2006; (Eichenberger Gilmore et al., 2005). Toxicity is uncommon, but high supplemental doses can cause bleeding, muscle weakness, fatigue, nausea, and diarrhea.

Folate is necessary for red blood cell formation and healthy cell growth. It's especially important early in fetal brain development which is why it’s found in prenatal vitamins. One cup of broccoli provides 85 mcg of folate. Folate deficiency causes anemia and is associated with a higher prevalence of depression, cognitive impairment, and dementia. Folate is generally considered non-toxic but daily intake should remain below 1000 mcg.

Vitamin K is necessary for blood clotting and keeping bones healthy. That same cup of folate-rich broccoli also contains 200 mcg Vitamin K, which meets daily recommendations and then some. Deficiency is rare, but newborn infants are at risk for vitamin K deficiency bleeding (VKDB; uncontrollable bleeding caused by blood failing to clot). The AAP therefore recommends a vitamin K shot for all newborns to prevent the potentially lethal VKDB. Excess vitamin K is not considered dangerous.

Try incorporating the vitamin-rich foods from the table above into your family's diet to ensure proper intake. Interested in looking up the vitamin content of your favorite foods? Check out this handy online tool.

Sources:

• Diab L, Krebs NF. Vitamin Excess and Deficiency. Pediatr Rev. 2018 Apr;39(4):161-179.

• Briefel R, Hanson C, Fox MK, Novak T, Ziegler P. Feeding Infants and Toddlers Study: do vitamin and mineral supplements contribute to nutrient adequacy or excess among US infants and toddlers? J Am Diet Assoc. 2006 Jan;106(1 Suppl 1):S52-65.

• Eichenberger Gilmore JM, Hong L, Broffitt B, Levy SM. Longitudinal patterns of vitamin and mineral supplement use in young white children. J Am Diet Assoc. 2005 May;105(5):763-72; quiz 773-4.