More Than 94% of Americans Fall Short on Vitamin D as Experts Urge Blood Tests

1 articles · Updated · Good Housekeeping · Aug 18

More than 94% of Americans do not get enough vitamin D daily, prompting nutrition experts to urge people to track intake and ask doctors for a blood test rather than rely on diet or sun exposure alone.
NIH guidance puts daily needs at 600 IU for most people ages 1 to 70 and 800 IU for adults 71 and older, while doctors may temporarily prescribe higher doses for confirmed deficiency.
Pregnant women, breastfed infants, older adults, people with darker skin, and those with liver, kidney, gut-absorption or obesity-related conditions face higher deficiency risk.
Vitamin D supports calcium absorption, bone health, immunity, mood, sleep and muscle strength, and low levels are linked to cardiovascular disease, autoimmune disease and depression.
Supplements can help, but experts warn excess intake can cause toxicity—typically from overuse of pills, not food or sunlight—so treatment should be guided by a clinician.