|
|
(HealthNewsDigest.com) – As of 2020 vitamin D is required to be listed on food labels. Most of us simply remember it as the sunshine vitamin we learned about long ago in high school biology class. Few of us think about this vitamin daily. Maybe we should. Adequate levels of vitamin D may be an important tool in your arsenal against Covid-19.
Vitamin D helps maintain a healthy immune system. Low levels increase your susceptibility to infection. Vitamin D also protects your bones and may prevent osteoporosis (adult bone thinning) and lowers your risk for cancer. That’s the good news. The bad news is that most of us don’t get enough of this important vitamin. There are few strong food sources – salmon, mackerel, tuna, and sardines – that we eat regularly. Milk is a good, but not great source of the vitamin.
Our best source of vitamin D may well be sunshine. When your skin is exposed to ultraviolet (UV) light it triggers vitamin D production. This is one of the few vitamins our bodies can make and the only one where we can get our full complement of the vitamin from sun exposure. The problem is most of us do not get enough sun and when we do we slather on sunscreen which blocks UV rays. Sunscreens with an SPF (sun protection factor) of 8 or greater will block enough UV rays to diminish vitamin D production.
Minorities have been hard hit by Covid-19. There are many reasons for this but one may be their levels of vitamin D. Research studies have shown over 40% of African American women have low blood levels of the vitamin. Melanin is the pigment that gives our skin color. People from Asia, Africa and the Middle East have more melanin and darker skin. This higher melanin content interferes with the body’s natural ability to produce vitamin D from sunlight.
Women who wear full robes and head covering for religious reasons, night shift workers who sleep during daylight hours, homebound elderly, and children who spend long hours inside may all get too little vitamin D. The season of the year, area of the country, time of day, cloud cover, smog, skin color, clothing, and your age all interfere with vitamin D production. Living in New England between November and February, you are unlikely to get enough sun exposure to provide adequate vitamin D. Living in a smoggy city, such as Los Angeles, will also cut down on D production
The vitamin is converted to its active hormone form in the liver and kidneys. Active vitamin D sends a message to the intestines to increase the absorption of calcium and phosphorus, two minerals vital to bone health. One of vitamin D’s major jobs in the body is to ensure adequate levels of calcium and phosphorus to form and maintain healthy bones. In a review of women hospitalized with hip fractures, 50% had signs of vitamin D deficiency.
Vitamin D is also necessary to enhance the function of immune cells that protect your body against invading pathogens. Experts have long recognized that adequate vitamin D is a good defense against our normal winter flu season. Many now feel that adequate levels may help protect against Covid-19.
If you are over 50, your skin produces vitamin D less efficiently and your liver and kidneys are less able to convert D to its active form. It’s tough to get enough vitamin D daily through food. Most adults need a supplement. The easiest way to get enough is to buy a calcium supplement plus vitamin D. Adults need 600 IUs (15mcg) of vitamin D daily and 800 IUs (20mcg) after age 71.
Since the 1930’s milk in the US has been fortified with vitamin D, a quart contains 400 IUs. Most adults drink too little milk and many suffer from lactose (milk sugar) intolerance reducing intake even further. Other dairy foods such as cheese and ice cream are rarely D fortified. Yogurt brands vary, some are fortified, and others are not.
Can you get too much vitamin D? Sunlight and food are unlikely sources of overexposure, unless you take large amounts of cod liver oil. It is easier to overdue supplemental vitamin D. The Food and Nutrition Board of the Institute of Medicine has set the daily upper limit for vitamin D at 4,000 IUs (100 mcg). Many experts now feel a blood test to check levels of vitamin D should be part of routine physical check-ups.
© NRH Nutrition Consultants, Inc.
Jo-Ann Heslin, MA, RD, CDN is a registered dietitian and the author of 30 books.
Available as eBooks from iTunes and Kindle/Amazon:
Diabetes Counter – the most up-to-date information on managing diabetes
Calorie Counter – a weight loss guide that won’t let you down
Protein Counter – put the latest protein recommendations to work for you
Healthy Wholefoods Counter – planet-friendly eating made easy
Complete Food Counter – food counts and nutrition information at your fingertips
Fat and Cholesterol Counter – newest approach to heart-healthy eating
Available in print from Gallery Books:
Most Complete Food Counter, 3rd Ed.
For more information on Jo-Ann and her books, go to: www.TheNutritionExperts.com or on twitter: #JoAnnHeslinRD.