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Natural Awakenings Greater Boston - Rhode Island

Simplifying Immune Support: Helpful Information about Vitamin D3 and Zinc

Sep 30, 2021 09:31AM ● By Gary Kracoff
Fall has arrived, in-person school and work has started and Covid-19 is still here making our lives even more complicated. With the cold and flu season coming soon, many people are wondering what to take for immune support, how much to take, how to take them, which ones need to be taken together and which must be taken alone. People aren't sure whether to take it with food, or on an empty stomach. After a while, it becomes confusing.

Two supplements that have many good, published studies on their immune supportive properties are zinc and vitamin D3. Here is some uncomplicated information to help explain why these nutrients may be beneficial for our immune health.


Key functions of zinc are immune support, white blood cell production (natural killer cells, t-cells and b-cells) which supports a healthy immune response, testosterone production, skin health and wound healing, eye health (especially the macula), normal growth and development, and taste and smell.

Zinc is difficult for the body to efficiently absorb on its own, so it is often attached to a chelating agent. Amino acids make great chelating agents as they are easily identified and assimilated in the body; this supports the transport of zinc into the gut and maximizes the bioavailability of zinc. Several studies have demonstrated the superior absorption of zinc bisglycinate, comprised of one zinc molecule bound to two molecules of the amino acid glycine. This form of zinc is absorbed intact (bound to glycine), so it does not compete with other minerals for absorption in the intestinal tract.

Studies suggest that zinc combined with the flavonoid quercetin may be beneficial in cases of viruses. Zinc can help block viral replication. For a virus to reproduce once it has entered the cell, an enzyme (RNA Dependent RNA polymerase) makes more copies of the virus. Zinc inhibits this enzyme, and at high concentrations in the cell, it may completely inhibit the virus from replication. Zinc does not readily enter our cells, but when it has an ionophore, the amount of zinc able to enter the cell rises dramatically. Quercetin provides that ionophore and allows zinc to get into the cell.

People at risk for inadequate zinc include vegetarians, people with certain diseases such as chronic renal disease, chronic liver disease, diabetes or sickle cell disease, Crohn’s disease or ulcerative colitis, people that misuse alcohol, pregnant or lactating women, older infants that are exclusively breastfed, and individuals that take too much copper (zinc and copper compete for absorption).

Chronic zinc ingestion can, however, lead to low copper levels. Copper is a necessary mineral and is a co-factor in many metabolic processes. If copper levels are out of balance, it can affect our histamine level, lead to iron deficiencies, cause symptoms including feeling cold, easy bone breakage, easy bruising, fatigue and getting sick easily or frequently. To simplify this concern, there is an easy blood test to test for zinc and copper levels and adjust dosages if necessary.

Vitamin D3

Studies suggest that optimal concentrations of vitamin D and K are beneficial for bone and cardiovascular health. Evidence supports that supplementation of Vitamins D and K together appears more effective than either taken alone. Vitamin D has the added benefit of metabolites which help to modulate immune function.

Research shows vitamin D is more like a hormone than a vitamin because of its ability to impact our entire system. In addition to bone health, vitamin D plays a significant role in cancer prevention (including breast, prostate, and colon cancer), immune support, bone health and energy, mood and brain support.

Too much or not enough vitamin D3 can affect our health. Lab values usually show normal as 25-95 nmol/l. A vitamin D3 level around 60nmol/l has been shown to be a good target level. Have an easy blood test taken to determine whether more or less vitamin D3 is needed. Knowing proper blood levels provides individuals with the best results from their vitamins/nutrients and removes the confusion and stress about what to take, how much to take and is it getting absorbed.

Figuring out the nutrients needed, the forms to take them in and the proper dosage does not need to be complicated or stressful. Simplify the process by asking a qualified practitioner what would be best for you. You are unique and there is a simple protocol that is right for you.

Dr. Gary Kracoff is a naturopathic doctor and registered pharmacist at the Johnson Compounding and Wellness Center, located at 577 Main St., Waltham. For more information, call 781-893-3870 ext. 2 or visit