New COVID-19 Study Reveals Major Vitamin D Deficiency Problem
Sufficient blood levels of 25(OH)D, the measure of vitamin D status, are considered to be greater than or equal to 20-30 ng/mL. Why a range? The National Academy of Medicine chose a conservative cutpoint at 20 ng/mL, while the Endocrine Society says 30 ng/mL. To put this in context, research estimates that 23% of the US population over the age of one have 25(OH)D levels less than 20 ng/ml, and 41% of American adults are below 30 ng/ml. These figures consider all vitamin D inputs, sunshine and diet.
Whether 20 or 30 ng/ml, let me be clear: These two numbers are not goals to aim for. Rather, they are cutoffs to avoid, since lower levels put you into vitamin D insufficient and deficient categories. You want your serum 25(OH)D level to be higher than 20-30 ng/ml, and consistently so. How much vitamin D will that take? Research from the late Robert P. Heaney, M.D. tells us the answer: 100 IU/day of vitamin D increases serum 25(OH)D by about 1 ng/ml in adults.
A little math, y’all: That means you need 2,000 to 3,000 IU/day of vitamin D3 to achieve those minimum cutoffs (20-30 ng/mL) of 25(OH)D. A few important notes: First, these intake levels assume no significant sun exposure (true for many of us during this pandemic) and that the person is a healthy weight. If an individual is overweight or obese, they may require two to three times more vitamin D to achieve that same 25(OH)D level. If a person has regular, significant sun exposure (other health considerations like skin cancer risk may come into play), they will need less vitamin D supplementation.
But remember, greater than 20-30 ng/mL is our goal for vitamin D status. In fact, some researchers and clinicians, including the Endocrine Society, actually recommend aiming for a higher range of 40-60 ng/mL. In adults, that would require 4,000 to 6,000 IU of vitamin D3 each day.