Mark Dry, the Scottish hammer thrower, might be feeling the effects of zinc intolerance but he was still able to find the strength to fend off a challenge from great rival Andy Frost at the Scottish Athletics Championships.

Dry launched a throw of 70.96 metres to defend his title at Scotstoun yesterday.

He had started the year in impressive form but arrived at the tournament short of full fitness and Dry revealed to Herald Sport last week that it will likely be months yet before the effects of ill-advised supplement use are entirely cleansed from his system.

Zinc intolerance has contributed to months of malaise for the 25-year-old. "My body's producing too much [zinc]," he said yesterday. "I was taking too many multivitamins as well. It all built up over time and after a while I just had too much in there. I won't be doing that again."

Securing the title should, though, be enough for the Highlander to have his name included in the initial wave of Commonwealth Games selections next month. Restored to prime shape by then, he will expect to be a contender in Glasgow. "I'm still ranked No.1 so I think I can do something there," he added.

Jax Thoirs needs to find further improvements if he is to win a medal but the young pole vaulter senses he is not far off the mark. The 20-year-old, now based near Seattle, secured the title with a best of 5.25m and then took aim at raising his own Scottish record to 5.51m. The Scotstoun wind extinguished his hopes yesterday but he will now focus on raising the bar in time to stand on the podium next summer.

"It's going to be tough but there's no reason I can't get up to 5.50 or 5.60 by next year," he said. "I definitely think that's in me. I won't be happy with anything less."

Guy Learmonth also prevailed in the 800m, which underlined the growing depth in Scottish middle-distance running. The Borderer's resolve was tested down the final straight as Jake Wightman, the European junior champion, refused to buckle. But Learmonth was able to edge out his training partner to win in 1:55.45 seconds.

"I want to do what I did last year," he said. "I was successful at the indoor season in March and April and I want to do that again, and then come outdoors all guns blazing. I need to get the Commonwealth time. I know it's there."

Elsewhere, Sarah Warnock took the long jump title in a Commonwealth standard of 6.27m, Kris Gauson won the men's 1500m and Steph Twell fought fatigue to claim the women's 1500m. "I was sinking slightly toward the end but it was worth it," said the UK champion.